1. Peel and coarsely chop 1 avocado; place in a blender. Add water, orange juice, honey, 3/4 teaspoon salt, 1/4 teaspoon black pepper, and red pepper, if desired; blend until smooth. Place in freezer to chill while chicken cooks.
2. Heat a grill pan over medium-high heat. Brush chicken with oil; sprinkle with remaining 1/4 teaspoon salt and 1/4 teaspoon black pepper. Place chicken in pan; cook 4 minutes on each side or until done. Remove chicken from pan; rub chicken with cut sides of garlic halves. Let chicken stand 10 minutes; cut or shred into bite-sized pieces.
3. Peel and dice remaining avocado. Stir diced avocado, corn, bell pepper, and onions into chilled avocado puree. Spoon chowder into bowls; top with chicken and cilantro. Serve with lime wedges.