In a bowl, mash the avocado and mix it with Greek yogurt, lime juice, garlic powder, onion powder, salt, and pepper.
Spread the avocado mixture evenly onto each tortilla.
Add shredded chicken, cheddar cheese, diced tomatoes, and lettuce on top.
Roll the tortillas tightly and slice them in half.
Serve immediately or wrap in foil for a grab-and-go meal.