Yeah, I'm occasionally guilty of this too, particularly on busy days where I'm running the roads.
I have an extensive recipe collection, most of which I've shared on this blog (the right hand side). On a day that has been really busy, I go there and look up anything I can throw together that doesn't require me to thaw meat. Usually a potato or pasta dish, like homemade macaroni and cheese. Having so many recipes to choose from is a life-saver, and to be honest I'm always on the look out for more. I am of the mind that you can't have too many recipes. Especially one's where you can easily switch out ingredients if you are out of something. (Oftentimes I just make up things. For example, Mexican spices, ground beef or leftover shredded roasted chicken, noodles or chips or tortillas, lettuce, tomatoes or tomato sauce or salsa, shredded cheese, and maybe some potatoes even and you can make a casserole on the fly. You can even top it with sour cream or guacamole and black olives. Maybe have some homemade Mexican or Spanish rice on the side.)
If you shop using a list, before you go to the grocery store spend some time and really plan your meals. For me, I don't use much of a list. Just from experience in making recipes over and over again, I know basically what I will need. (I try to be conscious of what I'm out of, and that actually does make my list. Can't do without baking soda you know.)
For instance, whole chickens are $1.09/lb so I'll pick up one of those and right away I know I'm having roast chicken, chicken noodle soup, and chicken pot pie. But maybe I'm feeling frisky and think, "Let's have Southwest Creamy Pasta Bake instead of chicken pot pie this week". I know this will entail certain ingredients I don't normally buy, so I'll pick up some cream of celery and black olives. The rest I normally buy anyway. We eat more chicken, turkey, and ham than any other meat, and I have go-to recipes for those I know by heart and keep ingredients for those all the time.
For me, I like to use leftovers so I make more at once anyway and throw them all together into a casserole or soup. My dinner does double- and sometimes triple-duty this way. It's a beautiful thing when I only have to spend a few minutes in the kitchen for dinner. It's effective if I go ahead and freeze those leftovers. I will usually have leftover shredded, roasted chicken in my freezer and it doesn't take long to thaw enough so I can use it. I can season it with some Mexican spices, throw it on some tortillas and cover it with salsa and cheese in a casserole dish and I'm done.
One other thing you can try that you will learn from is to cook for a whole day a weeks worth of meals. I did this when I worked. On the weekend I would make things like lasagna, spaghetti and meatballs, and manicotti, or pizza all in one day. They all have basically the same ingredients. You can do the same with Mexican food. Also on this day I would throw together a bunch of breakfast burritos and we were good for a week. I'd come home from work and throw one of my homemade dinners in the oven, throw together a salad and bread and we were good to go. This method can be used just as effectively if you stay at home.
If it's 3:00 and you don't know what's for dinner, have pancakes or breakfast for dinner. You could also try these from the recipes in my side bar:
Tomato Soup, Baked Potato Soup, or Egg Drop Soup (located under Soups)
Baked Oatmeal, Lentils and Rice, Baked Mac and Cheese, or Penne With Herbs Tomatoes and Cheese (located under Pasta and Grains)
Potato Casserole, Potatoes Ole, or Potatoes Puff (located under potatoes)