Step 1

Place the garlic on a baking sheet or in a broiler-proof skillet. Broil, turning halfway through, until the papery skin of the garlic is burned and the cloves soften, about 6 to 9 minutes. Peel. In a blender or food processor, working in two batches, combine the garlic with the achiote paste, chicken broth, bitter orange juice, oregano, cumin, allspice, salt, and pepper and puree until smooth.

Step 2

Slide the turkey, breast side down, into a heavy-duty plastic bag large enough to hold the turkey. Pour the marinade into the bag and massage it into the bird, working it into the cavity and all the crevices. Place the bag in a roasting pan and refrigerate for at least 12 hours, or up to 48 hours, turning the bird a couple of times to redistribute the marinade.

Step 3

Set an oven rack in the lowest position and preheat the oven to 450°F. Butter a baking dish.

Step 4

Spread the onions and tomatoes in a large roasting pan. Set the turkey, breast side up, on top of the vegetables in the pan (reserve the marinade). (Optional: stuff the main cavity with as much stuffing as it can hold. Place the rest of the stuffing in the baking dish; cover and refrigerate.) Close the cavity by crossing the legs and tying with butcher’s twine. Tuck the wing tips under the turkey. Pour the remaining marinade over the turkey.

Step 5

Roast the turkey for 30 minutes.

Step 6

Cover the turkey with the banana leaves, if using. Cover the top of the pan with aluminum foil, sealing it as best as you can. The less steam that escapes, the better. Reduce the oven temperature to 350°F, place the turkey back in the oven, and roast for 3 1/2 hours (or for at least 12 minutes per pound).

Step 7

Remove the turkey from the oven and carefully remove the foil and leaves, being careful, as the steam is hot. Baste the turkey generously. Raise the temperature to 400°F and return the turkey to the oven and roast for 15 minutes more. The meat should be completely cooked through and nearly falling off the bone. Remove the turkey from the oven and let it rest, loosely covered with aluminum foil, while you make the gravy. Leave the oven on.

Step 8

Meanwhile, strain the cooking juices into a medium saucepan, pressing on the solids with the back of the spoon to get as much liquid as possible; discard the solids. Set aside 1 cup of the liquid for the reserved stuffing. You will make gravy with the rest. Melt the butter in a saucepan over medium heat. Sprinkle the flour on top, mixing well with a wooden spoon, and cook for 3 to 4 minutes, letting it gently bubble, until the roux is golden brown. Add the rest of the liquid and simmer for 12 to 15 minutes, stirring occasionally, until it is a brick color and has thickened to the consistency of light cream.

Step 9

While the sauce thickens, pour the reserved 1 cup liquid over the stuffing in the baking dish and bake for 20 minutes, or until it is hot throughout and the top is crisped.

Step 10

Carve the turkey and serve.