To prepare the Calamari: In a small stainless steel bowl mix the calamari with jerk marinate. Warm a sauté pan with half of the olive oil over medium high heat. Add the calamari and sauté for 2-3 minutes. Slowly add the rum and simmer for another minute. Remove the calamari from the pan, keeping warm and reserve the cooking juices.
To prepare the Salad: In a large bowl, toss together the mango, jicama, peppers and watercress. In another small bowl, whisk together the pan juices with the remaining salt, olive oil, lemon juice, yogurt and crushed red pepper flakes. Pour this dressing over the salad and toss.
To Serve: In a large white oval platter, arrange the salad and spoon the warm jerked calamari on top. Garnish with freshly torn mint leaves.