Make the marinade. Place the garlic in a small microwaveable dish, cover with water and microwave for 1 minute. Drain and place in a blender jar. Add the ancho powder along with the spices and herb, vinegar, 1 1/4 cups boiling water and 1 1/2 teaspoon salt. Blend until smooth. Measure out 1/3 cup. Scrape the remainder into a container with a tight-fitting lid and refrigerate for another use.
Scrape the red chile adobo mixture back into the blender jar. Break up the achiote into the blender and add the oil and 1/3 cup water. Blend until smooth.
Make the salsa and sauce. Toast the chiles in an ungreased skillet over medium heat, turning them for a minute or so until they are aromatic and toasty smelling. Scoop into a small bowl, cover with hot tap water, weight with a plate and soak for about 30 minutes.
In the same skillet, roast the unpeeled garlic turning from time to time until blackened and in spots and soft, about 15 minutes. Cool and peel.
Roast the tomatillos on a rimmed baking sheet about 4 inches below a broiler until blackened and blistered on one side, about 5 minutes, then flip and roast on the other side. Cool.
Drain the chiles and scoop into a blender jar with the garlic and tomatillos (and all their juice). Blend to a coarse puree. Add enough water to give the salsa and easily spoonable consistency, then taste and season with salt. A little sugar can help bring out the chiles' natural fruitiness. Pour about 2/3 of the salsa into a serving dish. Pour the remainder into a small saucepan and add the orange juice and chicken broth. Bring to a simmer. Taste and add a little more salt and sugar if you think the sauce needs it. Keep warm on the side of the grill.
Finishing the dish. Heat a gas grill on medium-high to high or light a charcoal fire and let it burn until the coals are covered with a gray ash and very hot. Brush or spray the knob (or green) onions and pineapple slices all over with oil. Grill, turning regularly for several minutes, until they are richly colored and softening—you want them to still have a nice texture. Cut the core out of the pineapple, then chop the onions and the tender pineapple into small pieces. Keep warm on the side of the grill.
Brush or spray a perforated grill pan, grilling mat or double layer of heavy-duty foil with a little oil. then lay it on the grill. When hot, lay the fish in an uncrowded single layer on top. Smear or brush marinade over the fish—I like more than just a light coating. (Refrigerate any unused marinade for another dish.) Close the grill and cook until the fish flakes under firm pressure, about 15 minutes for fillets that are about 1-inch thick.
Use spatula to remove the fish to warm serving plates. In a bowl, toss the cabbage and cilantro with the lime juice and olive oil. Taste and season with salt. Spoon some of the warm pineapple-onion mixture over each portion of the fish, splash with the warm chile sauce, top with a little cabbage and cilantro, then carry straight to the table. Pass the salsa at the table for everyone to spoon on.