Step 1
Warm 1 tablespoon of rapeseed oil in a large non-stick skillet. Add 2 sliced onions and 2 chopped large garlic cloves, and sauté for 5 minutes, stirring often until they are softened.
Step 2
Add 2 diced large courgettes, 1 red and 1 yellow pepper (roughly sliced), along with 400g of chopped tomatoes, 2 tbsp of tomato purée, 2 tsp of vegetable bouillon, and 15g of chopped basil.
Step 3
Mix thoroughly, cover, and let it cook for 5 minutes. Resist the urge to add extra liquid since the vegetables will release a lot of moisture as they cook.
Step 4
Cut one large aubergine into slices. Arrange half of the aubergine slices in the bottom of the slow cooker, then layer 3 sheets of lasagne on top.
Step 5
Incorporate one-third of the ratatouille mixture, followed by the rest of the aubergine slices, 3 additional lasagne sheets, and then the leftover ratatouille mixture.
Step 6
Place the lid on and cook on High for 2½ - 3 hours, or until the pasta and vegetables have softened. Then, switch off the machine.
Step 7
Sprinkle 125g of vegetarian buffalo mozzarella on top of the vegetables, then cover and let it sit for 10 minutes to allow the cheese to melt and settle.
Step 8
Sprinkle some additional basil and accompany it with a handful of rocket.