Cheesy sausage, spinach and ravioli bake

Ingredients

• 6 good herby sausages
• 1 onion, chopped
• 2 clove garlic, crushed
• 2 cans chopped tomatoes
• 1 tablespoon tomato paste
• 1/2 teaspoon oregano
• 1/2 teaspoon thyme
• 1 teaspoon beef stock dissolved in 1 tablespoon of hot water
• 3/4 cup frozen spinach, defrosted, or 3 cups fresh chopped spinach
• 300 gram pack of meatless ravioli or tortellini – spinach and ricotta works well
• 1 cup grated mozzarella
• 1/4 cup Parmesan cheese
• salt and pepper