Begin by cutting skinless chicken thighs into bite-sized pieces. Toss with cornstarch, salt, and pepper until evenly coated. Set aside.

In a separate bowl, whisk together water, soy sauce, light brown sugar, sesame oil, and minced garlic until well combined. Set aside.

Heat olive oil in a large skillet over medium-high heat. Add coated chicken in a single layer and cook for about 2-3 minutes on each side until golden brown.

In the same skillet, sauté diced onions and sliced jalapenos for 4-6 minutes until onions are translucent.

Return cooked chicken to the skillet with the vegetables. Pour in the sauce mixture and stir gently. Cook for an additional 2-3 minutes until sauce thickens.

Serve hot over steamed jasmine rice, garnished with sesame seeds and sliced jalapenos if desired.