In sealable plastic bag, combine chicken and marinade of lemon peel, 2 tablespoons lemon juice, 2 tablespoons olive oil, garlic, salt and pepper. Seal bag and refrigerate for 30 minutes.
In bowl, whisk together remaining 3 tablespoons lemon juice, roasted garlic, remaining 1/2 teaspoons olive oil, sea salt and fresh ground pepper. Mix in tomato, green olives, capers, basil and avocado; set aside.
Remove chicken from bag and discard marinade. Grill over medium-hot coals for 4 to 5 minutes per side or to desired degree of doneness.