Spray a frying pan with olive oil or non-stick spray and place over medium-high heat. Scramble your egg and whites with the diced onion until fully cooked. Add chili powder to taste (more = more spicy). Stir half cup of black beans and warm through.
Lay whole-wheat tortilla open on a plate and fill with the egg and bean mix. Roll up into a burrito. Top with salsa, avocado and sour cream.