Preheat your oven to 425°F and line a baking sheet with parchment paper.
In a medium bowl, combine the self-rising flour and 3 tablespoons of the Greek yogurt, stirring until a dough forms.
Turn the dough onto a lightly floured surface and knead for 1 minute, then roll it out into a thin 8-inch circle.
Place the dough on the baking sheet and par-bake for 8 minutes until the edges are just starting to firm up.
While the crust bakes, toss the cooked shredded chicken breast with the buffalo sauce until evenly coated.
Remove the crust from the oven and spread the buffalo chicken, shredded mozzarella, diced red onion, and sliced celery evenly across the top.
Return the pizza to the oven and bake for an additional 8-10 minutes until the cheese is melted and bubbly.
In a small ramekin, whisk the remaining Greek yogurt with the dried dill, garlic powder, sea salt, and water to create a thin ranch drizzle.
Remove the pizza from the oven, drizzle with the prepared ranch sauce, and slice into wedges to serve.