Preheat the oven to 200 degrees Celsius.
Put the cauliflower florets on a parchment covered baking sheet and bake for 10-15 minutes until it starts to get golden brown.
Meanwhile prepare the tomato sauce by preheating a nonstick pan over medium heat.
Add the diced onion and minced garlic and fry for 3-4 minutes.
Add the tomato sauce, oregano, salt and pepper and let i simmer for 10 minutes.
At the end add the fresh basil.
Slice the zucchini using a mandolin until you have 12 slices.
When the cauliflower is ready, put it in a blender together with the tofu, natural yeast, mushrooms, lemon juice, olive oil (if using), salt and pepper and blend until you have a smooth ricotta-like texture.
Add about one tablespoon of ricotta to each zucchini slice and roll up.
Put half of the tomato sauce on the bottom of a oven safe pan.
add the rolls to the pan.
Add more sauce on top and sprinkle cheese over the rolls.
Cover with foil and bake for 15 minutes.
Turn on the grill/broil function and bake until the cheese is golden brown.