This potent seasoning is the lifeblood of Jamaican jerk—a paste fragrant with allspice and rum and fiery with Scotch bonnet chiles. It will keep for several weeks in a sealed jar in the refrigerator. (Line the lid with plastic so the chile fumes won’t corrode it.)
Step 1: Make the spice mix: Place the pimento berries, peppercorns, cinnamon, nutmeg, and pimento leaves (or bay leaves) in a spice mill and grind to a fine powder. You may need to work in several batches.
Step 2: Finish the jerk paste: Cut the Scotch bonnets in half. For milder jerk chicken, seed them; for more fiery jerk, leave the seeds in. (Wear rubber gloves.) Cut the scallions crosswise into 1-inch pieces. Rough chop the garlic and ginger. Place the chiles, scallions, garlic, ginger, thyme, and the ground spices in a food processor and finely chop. Add the soy sauce, vegetable oil, vinegar, rum, lime juice, and molasses and process to form a thick paste. Add salt and pepper to taste.