eggs - you can go simple, sunny side up, scrambled, etc. or you can make omelets (especially if nice veggies like mushrooms go on sale), fritatas, etc. You can go fleishig, e.g. salami or sliced hot dogs and eggs. And if you object to nitrates, you can buy the nitrate free kind; more expensive but a little will go a long way.
stuffed potatoes - bake potatoes (taste much better oven baked than nuked), cut off tops, scoop out insides, mash (mix with marg/butter, powdered soup mix or spices, milk, your choice), refill potatoes and bake for a few minutes. (This rebaking I do do in the microwave.) You can add all sorts of veg to the potatoes. Broccoli - frozen with a hechsher - may not be cheap but you can add a small amount and make it feel more luxurious without breaking the bank.
homemade pizza - making your own pizza dough is really easy, and doesn't always require proofing the yeast, which saves time. Another time saver - prepare the pizza the night before and put in your freezer, to bake when you get home if you work or are out during the day; just add a little extra to the baking time. As has been mentioned, buy the 5 lb. bricks and shred. I bought a good quality hand grater for about $6 - paid itself off in no time, and grating a lb. or two at a time only takes a few minutes. Incidentally, my kids noticed the improved quality of the cheese, much better than pre-shredded so they actually feel spoiled, as if we're getting the better stuff. (I guess we are ;-)