Cooking for one, as I do most of the time here in Cambridge, I often eat the same thing several days in a row. That's because things like a wedge of cheese, a package of tortillas, and a bunch of fresh herbs will last one person many meals, and I try not to waste too much food. Luckily, I don't mind this: when I find a good combination, it usually takes me quite a while to get sick of it.
Burritos are an easy, healthy and yummy lunch staple for me. I bring a package of the hand-made whole wheat ones from Trader Joe's to the department, keep it in our fridge, and then bring in fillings every day. The tortillas are best when warmed up slightly. Here are some of my favorite fillings:
1. Hummus and grated carrot (very simple, but surprisingly good)
2. Diced avocado, lemon juice, black beans, sweet corn and cilantro*
3. (2) with diced tomatoes
4. (2) or (3) with some sort of rice mixture (combine rice with cilantro and lime, or cook with onions, garlic and tomato for spanish rice, etc.)
I usually add lettuce to the fillings above, but I'm a big salad-in-sandwiches fan. Plain lettuce or a mixture of salad greens adds great freshness and crunch, which I love. You could add a little hot sauce or salsa to (2)-(4), or even a little yogurt or cheese, but they're not necessary.
*I also like this on its own, as a salad. Combine one avocado, about 2/3 can of black beans, about the same amount of sweet white corn (fresh in summer, frozen in winter), the juice of one lemon, and a sprinkle of cilantro. Or even leave out the cilantro, if you don't have any on hand. Mmm. Methinks the tartness of the lemon and the sweetness of the corn and avocado go very well together.