Soup is one of the most cost-effective meals you can make because you can make it in bulk, and the ingredients are just about always cheap. And you can put anything you want in soup, making it as healthy and tasty as you'd like.
Tortellini and spinach soup is easy to make. Just sauté some onion, red bell pepper, and garlic in olive oil. Sprinkle in some basil, oregano and crushed red pepper to taste. Add a dash of salt and pepper. Then, add diced tomatoes, chicken broth (veggie broth if you're a vegetarian) and spinach. Bring to a boil and add a package of frozen cheese tortellini. Continue boiling for a few minutes and you're done!