In a large bowl combine olive oil, garlic, basil, and oregano. Add chicken breast halves. Turn to coat chicken. Cover; marinate in the refrigerator for at least 4 hours, turning occasionally.
In a small baking dish, bake the chicken, covered, in a 350 degree F oven for 30 to 35 minutes or until tender and no longer pink. (Or grill over medium coals, uncovered, for 12 to 15 minutes, turning once.) Remove chicken from dish and slice into thin strips.
Spread 1 tablespoon pesto inside each pita pocket half. Stuff with lettuce and sliced chicken. Garnish with chopped green and red sweet peppers. Makes 4 servings.
Coat chicken with oil mixture as directed. Marinate in the refrigerator for up to 24 hours, turning occasionally.