In a large mixing bowl, combine the shredded chicken, tzatziki sauce, gluten-free pasta, spinach, cherry tomatoes, feta cheese, garlic powder, salt, and pepper.
Transfer the mixture to a greased baking dish.
Bake for 30-35 minutes, or until the pasta is cooked and the casserole is bubbly.
Let it cool for a few minutes before serving.
Notes
Feel free to add other vegetables like bell peppers or zucchini.
For a spicier version, add red pepper flakes.
This dish can be made ahead of time and stored in the refrigerator.