First roast your sliced aubergine, peppers and courgettes for 25 minutes at 180℃ / 350℉ with a little oil drizzled over them. Allow to cool.
1 aubergine (eggplant), 2 (bell) peppers, 3 large courgettes (zucchini)
Next, oil your slow cooker pot lightly to stop the cheese sticking.
In a bowl mix the red onion, garlic, tin of tomatoes, salt and pepper and oregano to make the tomato sauce.
1 red onion, 1 clove garlic, 400 g tin of chopped tomatoes, salt and pepper to taste, 2 tsp oregano
Place half of the sauce in the base of the slow cooker pot.
Top with slices of aubergine, peppers and courgette. Add half of the mozzarella pearls on top.
125 g mozzarella pearls
Do another layer - the rest of the tomato sauce, a layer of courgette slices, with the rest of the aubergine and pepper slices on top. Add the rest of the mozzarella pearls and a sprinkle a little oregano on top.
Cook on low for four to six hours.