In a large stockpot, combine the water, salt, sugar, whole allspice, garlic, habaneros, and ginger. Bring the mixture to a boil, stirring until the salt and sugar have completely dissolved, then remove from the heat and cool the brine completely before using. Once chilled, submerge the chicken thighs in the brine and refrigerate for 24 hours or overnight.

Add all of the jerk paste ingredients to a blender and blend until completely smooth. Reserve half of the jerk paste for basting later, then remove the chicken from the brine, pat it dry, and coat it thoroughly with the remaining jerk paste. Cover and refrigerate for another 24 hours to allow the flavors to fully penetrate the meat.

Prepare a charcoal grill for two-zone cooking and bring the temperature to approximately 400–450°F. Add two handfuls of soaked wood chips directly onto the hot charcoal to create authentic smoky flavor as the chicken cooks.

Place the chicken on the grill skin-side down over direct heat and cook, flipping every few minutes to prevent burning while developing a deep char. Continue grilling until the thighs reach an internal temperature of 175–180°F, moving them to the cooler side of the grill if flare-ups occur.

During the final 5 minutes of cooking, brush the reserved jerk paste over the chicken, turning frequently to caramelize the glaze without scorching it. The finished chicken should have crisp, flavorful skin with a glossy, smoky coating.

Transfer the chicken to a serving platter and let it rest for 5–10 minutes before serving. Garnish with sliced green onions and enjoy with rice and peas, grilled vegetables, or your favorite Caribbean-inspired sides.