Prepare the marinade by mixing chopped garlic, 2 tablespoons of oil, and the juice of one lime. Peel the shrimp and marinate them in the refrigerator for about 1 hour. Peel the fennel, removing the thick leaves, wash it, and cut it into thin slices. Heat 1 tablespoon of oil in a pan. Cook the sliced fennel and red pepper for 5 minutes. Mix with pieces of melon. Arrange everything in a dish with the marinated shrimp. Prepare a vinaigrette with the remaining olive oil and the juice of one lime. Season with salt, pepper, and pour over the dish. Before serving, garnish with mint leaves.