Pasta with a red sauce is one of the most frugal foods I know. This recipe is for a basic tomato sauce that can also be used in things like lasagna, or as a base for pizza.
1 Large Can Diced Tomatoes
1 Very Small Can Tomato Paste
1 Normal can of Tomato Puree
1 Tsp Dried Oregano
1 Tbsp Dried Basil
2 Garlic Cloves (finely chopped)
Cost per Serving : Approx $0.62
This is ridiculously simple. Take all of the ingredients and put them in a pan. Cover the pan, turn on a low heat, simmer for 20 minutes. That is all there is to it. You can add veggies like bell peppers or onions if you have some left over that need using up, but this sauce holds up really well on it's own. This will keep in the fridge for more than a week, or you can freeze it in Tupperware and defrost as needed.
Check out these other frugal recipes:
Stuffed Acorn Squash
Cheese and Egg Wrap