If you are using boneless chicken breasts, place them between sheets of wax paper and pound thin. If you have thin sliced chicken breasts, you are all set to go. If you haven't marinated the chicken beforehand, I suggest you do now. It comes out juicier and more fragrant. I use a quick marinade of olive oil, garlic, lemon juice and basil. Let marinade for at least and hour. You can slice the tomatoes, mozarella and peppers in the meantime and pre-heat the grill. Combine the mayonnaise and the pesto in small bowl; whisk to blend and set aside. Cut bread horizontally in half.

Sprinkle chicken breasts lightly with salt and pepper and place on the pre-heated grill over medium-high heat. Turn and grill chicken until just cooked through, about 6 minutes per side. Transfer chicken to a cutting board and let rest to cool slightly, about 3 minutes. You can also toast the focaccia bread on the grill until heated through.

Spread the pesto mayonnaise onto cut surfaces of bread. Layer the mozzarella, tomatoes, chicken, peppers and greens onto bottom halves. Top with bread tops. Buon appetito!