Whisk together tapioca flour and water from "sauce" ingredients in a small bowl and set aside.
Combine all the sauce ingredients together in a saucepan , then add the tapioca and water mixture to the saucepand and whisk to combin everything.
Cook the sauce mixture over medium heat for about 5 minutes until the sauce is thickened. Remove from heat and set aside while you prepare the chicken.
Whisk the egg in a shallow dish and place the tapioca flour in a seperate shallow dish and set aside.
Cut the chicken breasts into bite sized pieces and season with salt and pepper.
Dip the chicken pieces one at a time, first in the egg dish and then in the tapioca flour dish. Place dipped pieces on a paper towel lined dish.
Once all the chicken is coated, heat a non-stick skillet on medium-high heat with 1/4 cup of avocado oil.
Once the oil is hot, place chicken pieces, one at a time in a single layer in the skillet. Cook for 2-3 minutes per side until cooked through and golden brown. You may have to work in batches so as not to crowd the chicken. Set cooked chicken aside on a paper towel-lined plate.
Once all the chicken is cooked through, place all the chicken back in the skillet and pour the orange sauce over it and stir together so it is well coated and everything is heated through.
Garnish with chopped green onions, sesame seeds or some orange zest! Serve with cauliflower rice, steamed rice, or sauteed veggies. ENJOY!