Cut the chicken into 1-inch cubes. In a bowl, season with salt, black pepper, and garlic powder until evenly coated.
Add cornstarch to the seasoned chicken and mix well, ensuring each piece is well coated.
Heat avocado oil over medium-high heat in a large skillet. Add the chicken and sear until golden brown and crispy, about 5 minutes per side. Remove the chicken and set aside.