In a mixing bowl, combine the shredded chicken, mashed avocado, Greek yogurt, lime juice, garlic powder, onion powder, salt, and pepper. Mix until well combined and creamy.
Lay a tortilla flat on a clean surface. Spread a generous layer of the chicken avocado mixture over the tortilla, leaving about 1 inch of space around the edges.
Evenly distribute a handful of spinach leaves, diced tomatoes, and shredded cheese over the chicken avocado mixture.
Starting from one edge, carefully roll the tortilla tightly into a log shape. Repeat with the remaining tortillas and filling.
Once all tortillas are rolled, slice each log into pinwheels about 1 inch thick. Arrange on a serving platter.
For best flavor, cover and refrigerate the pinwheels for at least 30 minutes before serving.