Roasted Yams with Piri Piri Sauce and Sweet Spiced Seeds

Yams are something I barely ate growing up in the UK, and honestly I did not really encounter them properly until I moved to New Zealand. Now they are a firm winter favourite in my kitchen and I genuinely look forward to yam season every year. The piri piri sauce is something I used to make a lot when I was private cheffing in Switzerland, it is punchy, smoky, and deeply flavoured, and it works absolutely brilliantly with these sticky roasted yams. If you have never cooked with yams before, let me change that RIGHT NOW. These knobbly little things are an absolute TREASURE and massively underrated. Roasted until caramelised and tender, then piled with that sauce and finished with sweet and spicy seeds, this is the kind of vegetable dish that makes people forget they are eating vegetables. The sauce has heat, the seeds have crunch and sweetness, and the yams underneath are soft and gloriously sticky from the oven. It is a total flavour bomb and it is all on the table in under an hour. 

Watch me make this on YouTube!

Recipe Details

• Prep Time: 10 minutes
• Cook Time: 40 to 45 minutes
• Total Time: 50 to 55 minutes
• Serves: 2 as a side dish
• Difficulty: Easy
• Special Equipment: Air fryer (or oven), blender or stick blender

The secret to perfect roasted yams is cutting them in half and placing them cut side down on the tray. This gives you maximum caramelisation on the flat surface and a soft, fluffy interior. While the yams roast, you get the piri piri sauce going. The vegetables go into the air fryer for speed, but the oven works just as well. The sauce will taste fiercely spicy on its own, but once you add the yoghurt and vinegar it mellows into something balanced and deeply complex. Do not be alarmed by the heat at the tasting stage. Trust the process.

Why You'll Love This Recipe

• A completely different way to eat yams: Forget boiling them into submission. Roasting with the cut side down gives you sticky, caramelised edges and a fluffy centre that is completely DELICIOUS.
• That piri piri sauce: Smoky paprika, roasted peppers, chilli, garlic, and a dollop of yoghurt to cool it all down. It is a proper sauce with proper heat and it makes the whole dish sing.
• Sweet and spicy seeds for crunch: A quick stovetop seed mix with honey, cumin, and coriander that crisps up on baking paper and adds the most addictive crunch on top.
• Seasonal and budget friendly: Yams are a winter staple in New Zealand and incredibly good value. This recipe makes the absolute most of them.
• A vegetarian side that steals the show: This is the kind of side dish people ask about. It looks impressive, tastes exciting, and is genuinely easy to pull off.

Ingredients

For the Roasted Yams:

• 8 yams, scrubbed and halved lengthways
• Olive oil, to coat
• Salt and freshly ground black pepper

For the Piri Piri Sauce:

• 1 large chargrilled pepper from a jar, roughly chopped
• 1/2 onion, sliced
• 2 cloves garlic
• 1/2 tsp dried chilli flakes (reduce to 1/4 tsp for less heat)
• 1 tsp smoked paprika
• 10 fresh oregano leaves
• Olive oil, a glug
• Salt and freshly ground black pepper
• 3 tbsp natural yoghurt
• A good splash of vinegar (nectarine, apple cider, or any fruity vinegar works well, or make your own here)
• A small handful of fresh coriander

For the Sweet Spiced Seeds:

• 1 tbsp olive oil
• 1 tbsp honey
• 1/2 tsp ground coriander
• 1/2 tsp ground cumin
• A pinch of salt
• 2 tbsp flaked almonds
• 2 tbsp sunflower seeds

Instructions

1. Preheat the oven: Heat your oven to 190°C (170°C fan / 375°F / Gas Mark 5). Line a baking tray.
2. Roast the yams: Toss the halved yams in a generous glug of olive oil and season well with salt and pepper. Place cut side down on the lined tray and roast for 30 minutes. Check at 20 minutes. If they are already looking golden and caramelised, you may want to turn the oven up to 200°C (180°C fan) for the last 10 minutes to get some extra colour. They are ready when they are tender all the way through and the cut sides are gloriously sticky and golden.
3. Roast the sauce vegetables: While the yams are in the oven, toss the onion, garlic, and oregano leaves in a glug of olive oil and season with salt and pepper. Add the chargrilled pepper. Roast in the air fryer at 200°C for 5 to 7 minutes, then reduce to 180°C for a further 5 to 8 minutes until the onion is soft and cooked through. Alternatively, roast in the oven alongside the yams for 15 to 20 minutes. The sauce will taste very spicy at this point, that is normal.
4. Make the piri piri sauce: Transfer the roasted vegetables to a blender or use a stick blender. Add the smoked paprika, natural yoghurt, a good splash of vinegar, and fresh coriander. Blitz until smooth. Taste and adjust seasoning. The yoghurt and vinegar balance the heat beautifully. Add more of either if you want it milder or tangier.
5. Make the sweet spiced seeds: Heat the olive oil and honey in a small frying pan over medium heat. Add the ground coriander, cumin, salt, flaked almonds, and sunflower seeds. Stir to coat everything well and let it bubble for 2 to 3 minutes, stirring frequently, until the seeds and almonds are turning golden and the mixture smells toasty. Pour straight onto a sheet of baking paper and spread out to cool. They will crisp up as they cool.
6. Serve: Pile the roasted yams onto a serving plate or board. Spoon over the piri piri sauce generously and scatter the sweet spiced seeds on top. Serve straight away.

Chef's Tips

Always roast yams cut side down: This is non-negotiable. The flat cut surface on direct contact with the hot tray is what gives you that beautiful caramelisation. If you roast them cut side up, you miss all of that sticky golden goodness.

The sauce tastes very spicy before the yoghurt goes in: Do not panic. The yoghurt completely transforms the sauce, cooling the heat and adding a creamy richness that balances everything out. Taste it before the yoghurt, then taste it after. It is a completely different sauce.

Get the seeds off the heat before they look done: They will continue cooking in the residual heat of the pan and on the paper. Pull them off when they are just turning golden. A minute too long and they will burn.

Adjust the chilli to your preference: Half a teaspoon of dried chilli gives this a proper kick. If you are cooking for people who are sensitive to heat, start with a quarter teaspoon. The sauce should have warmth without being overwhelming once the yoghurt is in.

Use any fruity vinegar you have: Nectarine, apple cider, white wine vinegar, or even a good quality red wine vinegar all work. The vinegar brightens the whole sauce and stops it feeling heavy. If you want to make your own, there is a recipe on the site.

Substitutions & Variations

• No yams? Kumara (sweet potato) works beautifully here and is very easy to find year-round in New Zealand. Cut into halves or thick wedges and roast in the same way.
• No air fryer for the sauce vegetables? Roast them in the oven alongside the yams for 15 to 20 minutes. They just take a little longer than in the air fryer.
• No chargrilled peppers in a jar? Roast a fresh red pepper yourself. Halve it, brush with oil, and roast at 200°C for 25 minutes until charred and soft. The jar version just saves time.
• No fresh coriander? A small handful of fresh flat-leaf parsley works as a substitute. The flavour is different but still delicious.
• Want to make it vegan? Swap the natural yoghurt for a good quality coconut yoghurt. The sauce will have a slightly different flavour but the creaminess and balance will still be there.
• Want it less spicy? Reduce the dried chilli to 1/4 tsp and leave out the fresh oregano for a milder, sweeter sauce.

Storage

Best eaten fresh: The yams are at their absolute best straight from the oven while the caramelised edges are still a little crisp and the seeds are crunchy. Serve immediately if you can.

Fridge: Store leftover yams and sauce separately in airtight containers in the fridge for up to 2 days. Reheat the yams in the oven at 180°C for 10 to 12 minutes to revive some of the caramelisation. The sauce keeps well and can be used as a dipping sauce or dressing throughout the week.

Freezer: Not recommended for the assembled dish. The sauce can be frozen in a small container for up to 1 month. Defrost overnight in the fridge and stir well before using. The yams do not freeze well once cooked.

Store the seeds separately: Do not assemble the dish fully if you are planning to eat it over a couple of days. Keep the seeds in a small jar or container at room temperature where they will stay crisp for 3 to 4 days. Once they go on the warm yams they will soften, so always add them just before serving.

Frequently Asked Questions

What do yams taste like?
New Zealand yams (oca) have a slightly waxy, earthy flavour with a gentle tang when raw that completely disappears with cooking. Roasted, they become tender and naturally sweet with a slightly nutty edge. They are nothing like the large orange yams you might see in American recipes. Ours are much smaller and more delicate.

My yams are not caramelising, what do I do?
Two things to check: make sure they are cut side down on the tray, and make sure your oven is fully preheated before they go in. If they have been in for 30 minutes and still look pale, turn the oven up to 200°C (180°C fan) and give them another 10 minutes. A little extra olive oil also helps.

Can I double this recipe to serve more people?
Yes easily. Double all the ingredients and use two oven trays for the yams so they are not overcrowded. Crowded yams will steam rather than roast and you will lose all that caramelisation. The sauce and seed quantities double without any issue.

What if I don't have a blender for the sauce?
A stick blender works perfectly. If you have neither, chop all the roasted vegetables very finely and whisk together with the yoghurt, vinegar, and spices. The texture will be more rustic but the flavour will be just as good.

Can I use the sauce on other things?
Absolutely. It is brilliant as a dipping sauce for roasted vegetables, drizzled over grilled chicken or fish, stirred through grain salads, or spread in wraps. It keeps in the fridge for 3 to 4 days and gets better as it sits.

Can I make the components ahead of time?
Yes. The sauce keeps in the fridge for 3 to 4 days. The seeds keep in a jar at room temperature for 3 to 4 days. The yams are best roasted fresh, but you can prep them (halved, oiled, and seasoned) and keep them in the fridge for up to a day before roasting.

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Roasted yams are one of those winter vegetables that deserve so much more attention than they get, and this recipe makes a real case for them. The piri piri sauce brings heat and depth, the sweet spiced seeds bring crunch and sweetness, and the yams themselves,sticky, caramelised, tender, are the perfect base for all of it. Once you have made this, it will become your go-to way to eat yams every winter.

Enjoy!

Del x

Roasted yams with a smoky, creamy peri peri sauce and sweet spiced seeds. A bold, beautiful winter vegetable dish that is guaranteed to change how you think about yams.