Heat 2 tbsp of olive oil in a large saucepan. Add finely chopped red onion and cook for a few minutes until it becomes soft and transparent.
Add the canned tomatoes, frozen spinach, dried oregano and basil. Pour around 3 cups of chicken or vegetable stock. Alternative you can use water and 1 cube of chicken or vegetable stock. Season with salt and pepper. Bring the soup to boil and let simmer for a few minutes.
Add the tortellini to the soup and cook for about 5 minutes (check the exact cooking time on the package) until the tortellini are ready. Serve immediately.
Notes
In this recipe we used tortellini with spinach and ricotta, but you can choose your favorite.
Do not let the tortellini cook for very long, otherwise they may start falling apart.