Heat 1 teaspoon avocado oil in a large pan over medium heat. Add the minced ginger and chopped red pepper and cook until the pepper begins to soften, about 2 minutes.
Whisk together pineapple juice, white vinegar, tomato paste, onion powder, garlic powder, and a pinch of salt in a bowl. Pour the sauce mixture into the pan and increase heat to medium-high to bring it to a boil.
In a small bowl, whisk 1 teaspoon tapioca starch with 2 teaspoons of the hot sauce until smooth. While stirring the boiling sauce constantly, pour the tapioca mixture into the pan and continue stirring until the sauce becomes thick, reduced, and glossy, about 2–3 minutes. Taste and add sea salt as needed. Transfer the finished sauce to a large bowl and cover to keep warm.
Place 3 tablespoons tapioca starch and a pinch of salt in a large zip-top bag. Add the cubed chicken, seal the bag, and shake until the chicken is evenly coated.
Heat 1 tablespoon avocado oil in a large frying pan over medium-high heat. Add half the coated chicken and cook until golden and cooked through, about 2–3 minutes per side. Transfer to a paper towel-lined plate and blot off excess oil. Repeat with remaining oil and chicken.
Add the cooked chicken and drained pineapple tidbits to the warm sauce. Stir until all pieces are well coated and heated through.
Serve the sweet-and-sour chicken over hot cauliflower rice and garnish with sliced green onion and sesame seeds.
