Heat 1 tablespoon oil in 12-inch nonstick skillet over medium-high heat and cook chicken, stirring occasionally, until chicken is throughly cooked, about 5 minutes. Stir in 1 teaspoon Knorr® Chicken flavor Bouillon; remove chicken and set aside.
Heat remaining 1 tablespoon oil in same skillet and cook green peppers and onion, stirring frequently, until golden and very tender, about 8 minutes. Stir in garlic, cumin and chipotle and cook, 30 seconds. Remove from heat. Stir in remaining 2 teaspoons Bouillon. Stir in chicken and lime juice.
Serve in tortillas and garnish, if desired, with your favorite fajita toppings such as shredded cheddar cheese, sour cream and/or chopped cilantro.
Summertime Tip: Keep chicken breasts whole and cut peppers and onions in half, grill and then slice into thin strips.