Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Dice the chicken breast into small, uniform bite-sized pieces for even cooking.
In a small microwave-safe bowl, melt the ghee and whisk in the buffalo hot sauce until emulsified.
Toss the diced chicken in half of the buffalo sauce mixture until every piece is thoroughly coated.
Place the tortilla on the prepared baking sheet and spread the remaining buffalo sauce over the surface to act as the pizza base.
Evenly distribute the buffalo chicken and thinly sliced red onion over the sauce, then top with the shredded mozzarella cheese.
Bake the pizza for 8-10 minutes until the cheese is bubbly and the edges of the tortilla are golden and crispy.
While the pizza bakes, whisk together the Greek yogurt, dried dill, garlic powder, onion powder, sea salt, and black pepper in a small bowl to create the zesty ranch.
Finely dice the celery stalk to provide a fresh, crunchy garnish.
Remove the pizza from the oven, drizzle with the prepared ranch, and sprinkle the diced celery over the top before slicing.