I recommend a quality zaatar spice blend with the appropriate lemony sourness and dusky heat of sumac. I've also used aleppo chilli flakes – I love their peppery flavour as opposed to mouth-burning heat – but if you can't get your hands on any, replace with one teaspoon of chilli flakes.
4 cups natural yoghurt, strained to remove as much whey as possible
1 cup ricotta
5 tsp zaatar spice blend
4 small sweet potatoes, peeled and sliced lengthways into 0.5cm-thick slices
1½ tbsp olive oil
1 tbsp cumin seeds
2 tsp aleppo pepper flakes (or to taste)
fresh lasagne sheets (about 9)
800g jarred roasted peppers, juices strained
½ cup grated parmesan
¼ cup chopped coriander leaves
generous pinch aleppo pepper flakes
¼ cup crushed pistachios
Preheat the oven to 175C and line a large baking tray with baking paper. Grease a 30cm x 20cm x 12cm high baking dish with olive or ricebran oil – you can use any dish you like, but this size works well for about four layers.
Combine the yoghurt, ricotta and zaatar in a bowl. Cover and pop in the fridge until you are ready to assemble the lasagne.
Gently toss the sweet potato in the olive oil then lay the slices on the prepared tray in a single layer. Sprinkle over the cumin seeds and pepper flakes. Roast for about 15 to 18 minutes until it takes on some colour but is only just cooked through.
To assemble, line the baking dish with a sheet of lasagne. Place slices of cooked sweet potato on top in a single layer. Follow with a layer of roasted pepper slices. Smear over a generous amount of the yoghurt and ricotta mixture and repeat the process until the dish is full and the ingredients have been used, finishing with a layer of yoghurt mixture.
Sprinkle over the parmesan and bake for 40 minutes. If the top is taking on too much colour, cover tightly with foil and continue to cook, removing the foil for the final 10 minutes of cooking time.
Stand for 10 minutes. Sprinkle with chopped coriander, additional aleppo pepper flakes (if using) and crushed pistachios and serve.