Yehupetz.com

What's your favorite way to tweak the simplest of meals to enhance the flavor? Mine is to add a little lemon and coarse black pepper to canned white tuna in addition to a little hot sauce (which probably doesn't count here because it goes on everything).
I'm looking for more ideas because I am tired of eating the same lunch every day, but I don't have the time (or kitchen access) to cook a real recipe from Kosher.com or a cookbook; I just want to make a sandwich or something.

My goto sandwich is a bit different than most. I buy an eggplant salad or matbucha and eat it with rice cakes or other grain. It has great flavor and the one salad will last me for three to four days so it is very economical too (cheaper than tuna)