At its best, a jam-packed burrito can truly satisfy without weighing you down. The key is to focus on beans and vegetables—and be willing to eat whatever falls out of the tortilla with a fork (or, of course, your fingers).

Makes: 4 servings
Time: 30 minutes

Ingredients

• Four 8-inch whole-wheat flour tortillas

• 2 tablespoons olive oil

• 1 red onion, chopped

• 1 table…