Preheat the oven to 425°F. Line a baking sheet with parchment paper.
Finely pulse the cauliflower in a food processor until it reaches a rice-like consistency. Microwave or steam until tender, then let cool slightly and squeeze out as much moisture as possible using a clean towel.
Mix the drained cauliflower with the egg, 1/4 cup low-fat mozzarella, salt, and pepper. Press the mixture into a thin, even round shape on the parchment, forming your crust.
Bake the crust for 15-20 minutes until it starts to turn golden and feels firm.
While the crust bakes, grill or pan-cook the chicken breast seasoned with salt and pepper. Once cooked, dice the chicken into bite-sized pieces and toss it with the buffalo sauce.
Remove the crust from the oven, spread the buffalo chicken evenly over it, and sprinkle the remaining 1/4 cup of mozzarella cheese on top.
Return the pizza to the oven for an additional 5-7 minutes, until the cheese is melted and bubbly.
Remove from the oven, let cool slightly, then slice and serve.