Cut the aubergines and sweet potatoes into approx. 1 cm thick slices and place on a baking sheet lined with baking paper. Mix 4 tablespoons of olive oil with the spices and brush the aubergines and sweet potatoes with them and bake for 20 minutes at 180 ° C.
In the meantime, chop the onion and the cloves of garlic and sauté in a pan with 1 tablespoon of olive oil. Then crumble the tofu by hand and add it to the pan as well. Season with salt and pepper, pour the tomato sauce over it and heat briefly.
Now put a layer of the tomato-tofu sauce in a baking dish, over it a layer of eggplant, another layer of tomato-tofu sauce and then the sweet potatoes, continue doing this until everything is used up.
Pour the yeast melt over the eggplant-sweet potato lasagne and bake in the oven at 180 ° C for about 10 minutes.