Baked pasta shells filled with cheese

Name: Baked pasta shells filled with cheese
Ingredients: 16 conchiglioni rigati (large pasta shells); 1 quantity of tomato sauce (see below); 3 tbsp freshly grated Parmesan (or similar vegetarian hard cheese); 1 ball of mozzarella, sliced; 150g/5oz ricotta; 1 ball of mozzarella, finely chopped; 2 tbsp freshly grated Parmesan (or similar vegetarian hard cheese); 16 large fresh basil leaves; salt and freshly ground black pepper; 4 tbsp olive oil; 2 garlic cloves, finely chopped; 2 x 400g tins of plum tomatoes, chopped; handful fresh basil, finely chopped