Pasta al forno (italian baked pasta)

4 spoons extra-virgin olive oil,

1 onion,

1 garlic cloves,

1 bunch of basil leaves,

12 meatfree meatballs,

1 big augergine

600g fresh tomatos ( or puréed tomatoes),

500g rigatoni pasta,

200g mozzarella,

50g frozen peas,

4 tbsp grated Parmesan,

salt and pepper