In a bowl, combine the almond flour, tapioca flour, kosher salt and pepper. Using a fork, mix until well combined and there are no clumps.
In a separate bowl, combine the egg and the water and whisk until well combined and frothy.
Using one hand, grab a chicken breast and shake off the excess buffalo sauce. Dip the chicken breasts in the egg and flip to coat both sides, shake off excess. Using your other hand, then immediately dredge in the almond flour mixture to coat evenly all over. Shake off excess coating. Set on a clean plate and continue until all of the chicken is coated. (Using separate hands for each station prevents your hands getting too caked in the mixture and makes it easier to work with the chicken).
Heat the oil in a large skillet over medium-high heat. When the oil is hot (but not smoking) place the chicken into the skillet and fry until golden brown on each side and cooked through, about 4 minutes per side. Transfer cooked chicken to a wire rack until ready to serve.