Add the avocado oil to a large skillet and heat to medium-high.
Add the chopped red onion and sauté, stirring occasionally, until onion begins to sweat, about 2 to 3 minutes.
Sprinkle both sides of the chicken breasts with sea salt and place them in the hot skillet. Allow them to brown for 2 to 3 minutes per side.
Add the remaining ingredients to the skillet and stir everything around. Bring to a full boil, then reduce the heat slightly.
Continue cooking at a full, controlled boil until the sauce reduces by ⅓ to ½ its original volume and the chicken is cooked through, about 10 to 15 minutes.
Serve with your choice of sides and enjoy!