If you want a toaster oven, options open up. On a Dansdeals black friday special toaster, I've done salmon filets from Costco with salt and pepper, and they were delicious.
I do a lot of leftovers. Sometimes sandwiches - I use whole wheat bread to make it healthier and taste better. Anything from cheese mayo and tomato, PB&J (the type of Jelly makes a big difference, I use preserves or something similar), pastrami with mayo and mustard, etc.
Another option is a simplified version of a greek salad - romaine lettuce, tomato, cucumber, hard boiled egg, feta cheese sprinkled on top (Costco also has really good Tnuva feta cheese). if necessary, you can cut out some of the vegetables and it still works.