Preheat broiler. Drizzle chicken breasts with olive oil, salt, pepper, oregano, whatever. Put chicken on shallow pan with drainage, and shove under broiler, turning once, until chicken is browned on both sides. Let cool and slice thickly, you animal. 

Toast bread if you like. Spread pesto mayo on roll if you like. Slice tomatoes. 

Pile chicken, tomatoes, basil, cheese, and a slice or two of prosciutto, sprinkling with olive oil and balsamic vinegar, salt and pepper a few times as you layer.