Chicken And Basil Stir-Fry

Ingredients

• 1 1/2 pounds boneless, skinless chicken breast halves, cut crosswise into 1/4-inch-thick slices (longer pieces cut crosswise in half again)
• 1 tablespoon cornstarch
• coarse salt and ground pepper
• 6 teaspoons vegetable oil
• 1 small onion, halved and cut into 1/4-inch-thick wedges
• 2 bell peppers (red, green, or a mix, ribs and seeds removed), cut into 1/4-inch-wide strips
• 6 garlic cloves, minced
• 2 tablespoons rice vinegar
• 2 tablespoons soy sauce
• 1 1/2 cups fresh thai (see note) or other basil leaves larger leaves, torn in half
• cooked white rice, for serving (optional)