Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a small mixing bowl, whisk together the buffalo hot sauce and melted ghee until well combined.
Shred or dice the cooked chicken breast and toss it in the buffalo sauce mixture until every piece is coated.
Place the whole grain tortilla on the prepared baking sheet and bake for 3 minutes to lightly crisp the base.
Remove the tortilla from the oven and spread the buffalo chicken evenly across the surface.
Top the chicken with shredded mozzarella cheese, finely diced red onion, and thinly sliced celery.
Return the pizza to the oven and bake for 8 to 10 minutes, or until the cheese is melted and bubbly.
While the pizza bakes, prepare the ranch drizzle by mixing the Greek yogurt, dried dill, garlic powder, onion powder, sea salt, and black pepper in a small bowl.
Once the pizza is done, remove it from the oven and let it sit for 1 minute.
Drizzle the prepared Greek yogurt ranch over the top of the pizza, slice, and serve immediately.