Make sauce: mix all the stir-fry sauce ingredients in a bowl and set aside.
Heat pan: add 1 tablespoon oil in a large skillet over medium-high heat.
Cook chicken: add chicken to pan and sear for about 2-3 minutes per side or until browned. Set aside on plate.
Cook vegetables: add 1 tablespoon oil, broccoli, bell pepper, carrots, pineapple, and onion to same pan. Stir frequently and cook 5-6 minutes until onions are translucent and vegetables are cooked. Work in batches if you need to so the vegetables aren’t too crowded in the pan. If veggies still aren’t cooked to your liking and are getting brown too quickly you can always add a couple of tablespoons of water to the pan to help prevent them from burning.
Add: stir-fry sauce and chicken back to pan with all vegetables and stir to coat. Cook for 2 more minutes then serve.