Ratatouille pie

Ingredients

• olive oil
• 2 red onions
• 2 mixed-colour peppers
• 2 courgettes
• 1 large aubergine
• 2 cloves of garlic
• 4 black olives (stone in)
• 2 x 400g tins of plum tomatoes
• 1⁄2 a bunch of fresh basil (15g)
• 6 sheets of filo pastry (270g)
• 250g ricotta cheese
• 50g ground almonds