I always cook my ground beef at home and freeze it in baggies to take to WDW. When we are there, I can turn it into taco meat, spaghetti sauce, sloppy joes, etc....
Once time we took baking potatoes ( they don't crush or bruise in the luggage!). We topped them with salsa, ground beef, cheese, & sour cream.....yum! I also cooked meatloaf at home and took it frozen.
I have found that I can take frozen juice boxes, frozen beef, frozen lunch meat, etc.... in a collapsable cooler. It stays frozen after 10 hours from home, on the plane, and into the villa. In fact, it was still hard as a rock!
I also make a big batch of mac & cheese. With the leftover, I had cooked, ground beef, a can of cram of mushroom soup, and a small can of french fried onions. Bake it (or nuke it) until it bubbles. (All things that can be taken from home in the luggage).
I usually cook 4 or 5 meals per week but I never plan on going to a grocery store. I take lots of stuff from home and just add bread, taco shells, chips, & perishables from the resort store. I use the extra luggage space for souvenirs for the trip home.