In a blender, combine allspice, thyme, cinnamon, nutmeg, black pepper, salt, green onions, habanero peppers, garlic, ginger, soy sauce, vegetable oil, lime juice, and orange juice. Blend until smooth to create the jerk marinade.

Place chicken thighs in the slow cooker and pour the jerk marinade over them, ensuring each piece is evenly coated.

Cover the slow cooker and set it to cook on low for 8 hours or on high for 4 hours.

Once cooked, the chicken should be tender and infused with flavors. Optionally, for a crispy finish, place the chicken under a broiler for 2-3 minutes.

Serve the jerk chicken with a side of rice and peas or fresh salad.