Cut your chicken breast into bite-sized pieces, roughly 1 to 1.5 inches each.

In a medium bowl, combine the chicken pieces with 2 tbsp cornstarch, 1/2 tsp salt, and 1/4 tsp black pepper. Toss until coated.

In a small bowl, whisk together 3 tbsp sweet chili sauce, 3 tbsp low-sodium soy sauce, 1 tbsp light brown sugar, 1 tbsp cornstarch, 1 tbsp rice vinegar, 1/2 tsp garlic powder, 1/4 tsp ground ginger, and 1/4 tsp red pepper flakes (if using) until smooth.

Heat 2 tbsp canola oil in a large skillet over medium-high heat.

Add the cornstarch-coated chicken in a single layer. Cook for 3 minutes without stirring, then flip and cook for an additional 2-3 minutes until golden and cooked through (165°F internal temperature). Transfer to a plate.

In the same skillet, add the green beans and sliced onion. If needed, add 1 tsp canola oil.

Cook for about 4-5 minutes, stirring occasionally, until the green beans are vibrant and tender-crisp.

Return the chicken to the skillet and pour the sauce over everything. Stir well to coat.

Cook for an additional 2-3 minutes until the sauce thickens.

Remove from heat and sprinkle with toasted sesame seeds. Serve immediately over rice or noodles.