Preheat your oven to 450ºF and line two half sheet pans with parchment paper.
Add the halved brussels sprouts to one sheet pan and toss with the olive oil, salt, and pepper. Place each half cut side down and set aside. Add the frozen chicken bites to the other sheet pan.
Place the brussels sprouts on the middle rack, and the chicken on the bottom rack in the oven. Bake for 20 minutes before rotating the chicken to the middle rack and the sprouts to the bottom rack. Bake an additional 10 minutes until the chicken is golden brown and the sprouts are browning on both sides.
Once the chicken and brussels sprouts are in the oven, mix the bang bang sauce ingredients together in a large mixing bowl. Cover and set aside at room temperature.
Once the chicken is crispy golden brown, toss it with the bang bang sauce. Garnish with sliced green onion and toasted sesame seeds over rice with the roasted brussels sprouts.