Egg-amole (Mexican Egg Salad with Avocado and Greek Yogurt)

hard-cooked eggs, finely chopped (see note)

avocado, pitted and mashed

nonfat plain Greek yogurt

kosher salt

black pepper

medium tomato, seeded and finely chopped (to equal about 1/2 cup)

Optional for serving: whole-grain chips or tortillas (for dipping), or whole-wheat bread and toppings such as lettuce and sliced tomatoes (for sandwiches)