Homemade manicotti. It's so easy and inexpensive to make up a huge batch of these little crepes, then you can stuff them with just about anything and top them with your favorite sauces and cheeses. It's even easier if you go down to the dollar store and pick up a cheap small pan, like 5-6 inches wide at the bottom, so it makes all the crepes the exact same size every time. I measure my batter out with a mini ice cream scoop which is just enough to cover the bottom of the small pan. Then I stack each crepe between sheets of wax paper until I am ready to use them. A ricotta, egg and herb filling is traditional, with some tomato sauce on top, but they are also good stuffed with spinach and cheese too. A caramelized onion and mushroom filling with a cream sauce on top would also be cool.
Sardines are a great option too, and go well with eggs. There is a "fisherman's breakfast" recipe which simply calls for some sardines places into an oven safe bowl, topped with some tomato sauce and a couple eggs cracked into it, then you bake the whole thing. Sardines have omega 3's and lots of calcium and other nutrients.
Curried potatoes with peas over steamed rice is also very filling, and something out of the ordinary if you don't normally eat curries.
It's also really easy to stretch inexpensive meat, when making chicken or steak philly sandwiches. Just pick up some green peppers and onions that are on clearance and about to go bad, and chop them all up to bulk up the meat - freeze whatever extra you can't use right away. If you take the time to partially freeze the meat, then shave it super thin, it will make it look like a lot more than it really is when cooked with the peppers and onions.