Heat the avocado oil in a large skillet over medium heat. Add the chopped yellow onion and saute, stirring occasionally, until translucent, about 5 minutes.
Add the garlic and chopped chicken. Allow chicken to sit untouched 2 to 3 minutes to brown. Stir in the thai chilies and continue cooking, stirring occasionally, another 2 minutes.
Pour the sauce into the skillet with the chicken and bring to a full boil. Reduce heat to a simmer and allow it to cook, stirring occasionally, until chicken has cooked through, about 5 to 10 minutes.