We go backwoods camping quite a bit (as in, no bathroom facilities, no shower, no electricity whatsoever) because it's cheap. Can't beat $10/night! We have a one-burner cooktop, a cast iron dutch oven with a tripod, and a travel-sized grill to use.
-- grilled corn (and whatever other veggie you prefer) wrapped in aluminum foil, sprayed with nonstick cooking spray and seasoned with salt and pepper.
-- hot dogs. not the greatest, but they are easy to cook over an open fire and great for kids.
-- beans in the dutch oven over an open fire. You can do any sort of bean -- we typically do baked beans -- although we have done kidney beans (canned), grilled sausage on the grill and cooked rice in the boiler on the cookstove to make jambalaya.
-- fish on the grill
-- baked potato on the grill or thrown in the open fire (wrapped in aluminum)
For breakfast we tend to keep it simple...pretty much grits, oatmeal, or bagels. You can even keep cream cheese in the cooler. My dad somehow makes awesome biscuits in the dutch oven, but I have no clue how.
For lunch, we eat pre-made sandwiches or leftovers.