I was getting a week's food off $25-30, but this was about a decade ago so prices are probably more like $30-35 now. Also, I live in a rural area with loads of farms, so prices might be abnormally cheap.

Buy a dozen eggs, 2 loaves of cheap bread, 1 gallon of milk, and butter/spices as you run out. Breakfast will be eggs and buttered toast. Buy some jelly as a treat if you have money left over. Drink milk as you like with breakfast and dinner.

For lunch/dinner, I had 3 dishes I would make in rotation. One of them would last me 3-4 days, so I was only cooking those meals twice a week. All three cost about $10-15.

Dish one was chili. 1lb dry beans, 1lb Jimmy Dean hot sausage or other spiced ground pork product, 1 big onion, 1 can of RoTel or other canned hot peppers, 2 cans tomato sauce, 1 can diced tomatoes, some red bell peppers, and your favorite hot sauce. Soak beans overnight. Boil the beans for at least 10 minutes, then drain and put them in a crock pot with the canned ingredients. Chop up the fresh veg and add them, and mix in the ground pork. Season with cumin, oregano, garlic powder, and smoked paprika or chipotle. The sausage should have enough salt already that more is not needed. Cook on low while you're at work. Serve with hot sauce and toast with garlic powder and salt on top for cheap-ass garlic toast.

Dish two was chicken soup. Get the cheapest chicken available, carrots, onion, celery, chicken bullion cubes, and egg noodles. Dice the chicken and veggies. Put in a stock pot. Add 3 quarts to 1 gallon of water. Add 1 cube per quart of water. Add lots of pepper and garlic powder, 2 bay leaves, bring to a boil and simmer. Check halfway through cooking if you need some more salt or if the bullion was enough. When veggies are soft and chicken is cooked, remove the bay and add the noodles. Simmer until noodles are almost done, they'll keep cooking once you remove the pot from the heat. Once again, several with garlic toast (what can I say, it's a cheap source of carbs and fat!).

Dish three was burrito bowls. Buy 1 lb beans, 1 lb Jimmy Dean hot sausage or similar, 1 big onion, a 5lb bag of rice, fresh jalapeno or Serrano peppers, and your favorite hot sauce. Soak beans overnight. Boil beans for 10 minutes, then put them in the crock pot. Chop the veggies and add them. Mix in the sausage. Season with garlic powder, cumin, and smoked paprika or chipotle. Add just enough water to cover everything, then add 1 cup more. Cook on low while you're at work. When done, cook some rice. Make a big bowl of rice, then mix in a big ladle-full of the beans. Add hot sauce to taste. Looks like dog food, but tastes like heaven.