Swordfish Skewers with Escoveitch Tartar Sauce

Name: Swordfish Skewers with Escoveitch Tartar Sauce
Ingredients: 1 Scotch bonnet or habanero chile, halved; 1/2 small onion, thinly sliced; 7 allspice berries, cracked; 1 bay leaf; 1/2 cup rice vinegar; Pinch of sugar; 1 small chayote—halved lengthwise, seeded and cut into 1-by-1/4-inch matchsticks; 1 carrot, cut into 1-by-1/4-inch matchsticks; 1/2 cup finely chopped flat-leaf parsley; 1/2 teaspoon finely grated lemon zest; 1 tablespoon fresh lemon juice; 1 cup mayonnaise; Salt and freshly ground pepper; 2 pounds skinless swordfish steaks (1 inch thick), cut into 1-by-2-inch pieces; 24 cherry tomatoes; Vegetable oil, for brushing