Another flavorful, cheap meal is Thai curry over rice. Try and find the curry packet in paste form, since it's more forgiving and won't clump. Aside from the paste, all you need is coconut milk (usually comes in a tin) and whatever veggies/protein you'd like to add. I like to do potatoes, sliced onions, carrots, eggplant, and whatever chicken is cheap - usually legs or thighs in my area).
If you add potatoes, I'd highly recommend soaking the chopped pieces in cool water for like, 20 min to get rid of most of the starch. Then, roast the outside (inside can be a bit under, since it'll be cooking in the curry with the other veg for a bit). I prefer this, because uncooked, starchy potatoes will just come apart and make your curry a mash. Still tastes good, but having a clearly-definted saucy texture makes it more pleasing to eat.
If you can't find Thai green curry powder at your local supermarket, it's available for cheap online. You can also just cook protein in it (still add the coconut milk) if you're feeling lazy and want a quick, flavorful meal.
E: autocorrect