In a bowl, whisk together arrowroot powder, salt, pepper, onion, and garlic powder until combined
Add chopped-up chicken to the bowl and toss until coated
Heat oil in a skillet over medium-high heat. Once hot, add the coated chicken pieces (work in batches if necessary; if the pan is overcrowded the chicken will not cook through).
Pan-fry the chicken, turning regularly, until cooked through and coating is golden. Remove the chicken from the pan and put to one side in a bowl.
Reduce skillet heat to low. Add butter to the pan and hot sauce. Whisk until smooth.
Add the chicken back to the pan. Toss in the sauce until thoroughly combined and the sauce has thickened, about 5 minutes.