Corn masa spaetzle! Very cheap, except the cheese (even at the local el cheapo grocery store, the block of Havarti cost as much as everything else put together, but you can substitute pretty much any cheese and it'll work), and outrageously filling (this makes about 2 plates full, but each is enough food for 3 meals, and I'm a big eater).
I make no promises of authentic German cooking chops.
300 g corn masa
400 g wheat flour
6 eggs
1 tbsp oil
4 yellow onions
4 oz butter
8 oz Havarti cheese
Water, salt, pepper, extra flour/masa
So, the first thing you do is chop up your onions and start them cooking in the butter. Switch off the heat (but leave them on it) just when they start to caramelize.
Meanwhile, start a pot of water boiling. Add salt to taste.
Mix your masa and flour together. In a separate bowl, stir together the eggs, oil, and a bit of water (probably just under a quarter cup - I didn't measure, but undershoot rather than overshoot, since it's easy to add more water later). Add a pinch of salt and a sprinkle of pepper. Pour that into the flour/masa, and mix it together. Once you've got chunks of fairly dry dough moving about in the powder, turn it all out onto a surface you've coated with your extra flour/masa (either works). Start kneading and slowly adding water, maybe a tablespoon at a time, until it all holds together. Keep kneading until you've got a smooth, heavy, homogeneous dough. Press it down to about 1/2 inch thick, then use a knife to cut it into cubes*. Put the dough into the boiling water. When all of it's floated up to the surface for about a minute, it should be done.
Drain the cooked dough, then return it to the now-empty pot, along with the caramelized onions and butter, and fry it all up for about a minute. Serve with cubes of cheese.
*This produces a vastly oversized result compared to what's standard, but it's how I've come to do it. Smaller pieces are more work, but cook faster and are going to be more moist. If you have a cheese grater or something, that would produce more usual pieces. Your dough should absolutely be thick enough for that to be feasible.
EDIT: Yeah, ~5000 calories for the batch says my estimate for how much food this is is not far off.