Cube chicken breasts and place in a small bowl. Sprinkle with cornstarch and toss until well-coated. Season with salt and pepper.
Heat 2 tablespoons of olive oil in a large frying pan. Add chicken and cook for about 4 minutes per side, or until golden-brown and cooked through. Remove the chicken from the pan and set aside.
In the frying pan, add the chopped peppers and onion; saute for about 5 minutes, or until the vegetables are tender in texture. Add the minced garlic, minced ginger, and dried chilies. Cook for an additional minute. Place the cooked chicken back into the pan with the vegetables.
In a small bowl, mix the stir fry sauce ingredients together until the brown sugar has dissolved.
Pour the sauce over the stir-fry meat and veggies. Simmer for about 1 minute, or until the sauce slightly thickens.
Garnish the szechuan chicken with sesame seeds and serve on a bed of rice.