Step 1Blanch green beans 30 seconds. Drain and reserve.
Step 2Spray large skillet with nonstick cooking spray and heat over high heat 1 minute. Add oil and cook garlic until lightly browned, about 20 seconds. Stir in curry paste and lime leaves, if using, and cook until leaves start to turn translucent, 30 seconds.
Step 3Add chicken and saute until chicken is just barely pink, about 2 to 3 minutes. Fold in green beans and cook 30 seconds. Add fish sauce, sugar and pepper. Cook until chicken is cooked through and beans are coated with the curry sauce, about 3 minutes. Add bell peppers and cook 30 seconds.