For dinners and lunches, buy grains like rice, bulgar, farro in bulk. International grocery stores sell big bags on the cheap. Buy protein in bulk at a store like Aldi. Simple meals are 2 parts grain, one part protein, one part vegetable. Sautee or roast and sauce.

Breakfast, buy oats. Lots of ways to do oatmeal/hot cereal.

Cooking for yourself is the cheapest way to eat. My wife and I spend around $120 per week for all the meals for a family of 4 because we can cook.