Make food in quantity, then live off of it for as long as it lasts. Here's a few ideas.
Peel and cut up about 4 pounds of zucchini, bok choy, or other chinese vegetable. Throw it in a deep kettle at med-high heat that has a half cup of water, 1/2 tsp of salt, and any other spices you like. I usually just use black pepper. If you want more flavour, sauté spices in some olive oil in the bottom of the kettle before adding the water and salt. Stir thoroughly every 5 minutes until its cooked but still firm.
When you buy lettuce, clean & drain it as soon as you get home. Line it in plastic bags with a few folded pieces of white paper towel to absorb moisture. You will always have an easy supply of edible lettuce this way.
If you know how to prepare Rapini or other blanched-then-sautéd greens, make it in large quantities.
Buy the biggest chicken you can find. Remove the skin and drop it in a kettle of boiling water for no more than an hour. During that hour prepare all the vegetables, tubors and grain (a cup of short grain brown rice or quinoa), and spices you want to go into chicken soup. Remove the chicken from the water and dump in the veggies. While the veggies are simmering, remove all the meat from the bones. When the veggies are ready (based on your preference for firmness, not more than an hour), add the meat. Done.
Buy skinless boneless chicken thighs, trim the fat, and line them in a corning or pyrex pan. Add spices and salt, cover and cook in the microwave using the automatic meat setting (do not use the standard full power setting). The microwave has a way of extracting the fat from the meat. If you want better taste, using a real oven and put more effort into chopping veggies, laying open the thighs and spicing them before lining them into the pan.
Get a few pairs of the biggest chicken breasts you can find, put them in an oven pan. Then mix a big can of crushed tomatoes with plenty of fresh minced garlic, pepper and dried basil. Pour the tomato mixture over the breasts, cover and bake in the oven. This super easy method works on other kinds of meat too. If you have a bigger pan, increase the quantity and freeze the extra.
Buy cubed veal or pork, enough to mostly fill your slow cooker. Cook it up with minimal veggies and favourings, or lots of extra stuff, depending on your preference. I sometimes surf the net looking for ideas on how to improve flavour.