Huevos Rancheros comes to mind. Cook some chorizo, throw some diced onion in peppers in the hot chorizo fat, and when they’re done add some beaten eggs and mix it all together. Serve with rice or some tortillas and it will last a few days in the fridge.

Cheap, tasty, fast, easy, and fairly high in protein. You can also reduce the amount of leftover chorizo fat in the pan to lower the Kcal if that matters to you.