Crush the jerk seasoning ingredients together with a pestle and mortar or combine them in a spice grinder. You can multiply the recipe and store the seasoning in a sealed jar

Mix the oil, jerk seasoning and the juice from 1 of the limes together

Flatten the chicken slightly by placing each breast between sheets of cling film and bash them with a rolling pin. Don't go crazy, just take them to a uniform thickness so they cook evenly

Toss the chicken in the marinade and let sit for 10 minutes

Spread each bun with a tablespoon of mayo then assemble with the chicken, mango, lettuce and tomato, squeezing the leftover lime juice over before putting the bun tops on