Marinate the meat (or cauliflower). In a blender combine the garlic, lime, oil, Worcestershire, agave syrup or honey, chile, black pepper, oregano and 1 ½ teaspoons salt. Blend until smooth. If using flank steak, lay it in a 13x9-inch glass or stainless baking dish, pour the marinade over it, then use a pair of tongs to pick it up and allow the marinade to run underneath, coating both sides. If using cauliflower, cut off about an inch of 2 opposite sides, then cut what remains into about 1-inch steaks (you should get 4 to 6 steaks, depending on the size of the heads). Pour about 2 tablespoons water into a microwave-safe bowl, sprinkle each cauliflower steak with salt, lay them in the bowl, cover (if using plastic wrap, poke a couple of holes), and microwave at 100% power for 3 ½ minutes, until nearly tender. Use tongs to spread them out onto a rimmed baking sheet and brush the marinade over both sides of each steak. Cover beef or cauliflower and set aside at room temperature. (If you’re not cooking the recipe straight through, you can refrigerate the meat for up to 4 hours; let come to room temperature before grilling.)
Toast and soak the chiles. Heat a skillet over medium and, a few at a time, toast the chiles, pressing them flat against the hot surface for several seconds with a metal spatula until they change color and release their aroma, then flipping and toasting the other side. Collect into a bowl, cover with hot tap water, weight with a plate to keep them submerged and rehydrate for 20 to 30 minutes.
Make the sauce. Heat the lard or oil in a large (4-quart) saucepan set over medium-high. Add the onion and garlic and stir for 5 minutes or so, until the onion is browned a little, but not completely soft. Remove the pan from the heat and using a slotted spoon, transfer the onion and garlic to a blender or food processor, squeezing them to leave behind as much fat as possible. Use tongs to transfer the chiles from their soaking liquid to the blender, then measure in the cumin, black pepper and oregano. Add 2/3 cup of the broth and blend/process until as smooth as possible. Set the saucepan back over medium-high heat and when the fat is hot enough to make a drop of puree sizzle sharply, set a medium-mesh strainer over the pot and press the puree through. Stir for 7 or 8 minutes, until it is darker in color and very thick. Add the remaining 1 cup of the broth, the orange juice and the vinegar. Simmer, partially covered, for 30 minutes or longer to bring the flavors together.
Grill. Heat a gas grill to medium-high or light a charcoal fire and let it burn until the charcoal is covered with ash and quite hot. Generously spray or brush the flank steak or cauliflower steaks with oil. With tongs, lay on the grill oiled-side down. Oil what is now the top side. Grill flank steak for 5 or 6 minutes (depending on how hot your fire is), until richly browned (even a little charred) underneath, then flip and grill the other side. (Cauliflower will need about half as long as flank to get richly browned.) With a medium-high gas grill or a charcoal fire that’s quite hot, flank steak will cook to medium in 10 to 12 minutes total grilling time.
Serve. If the sauce has thickened beyond the consistency of a light cream soup, thin it with a little extra broth or water. Taste and season with salt, usually about 1 ½ teaspoon (depending on the saltiness of the broth), and with sugar—it usually takes about 2 teaspoons to bring out the fruitiness of the chiles. Slice the flank steak across the grain into thin slices—the pieces look nicest when sliced on a bias rather than straight down. Divide them (or the cauliflower steaks) among warm dinner plates, spooning sauce over or under the meat (or cauliflower). Scatter on the olives and pickled chiles and you’re ready to serve.
Other uses for adobo sauce: Cubed pork or lamb shoulder—browned in pork lard—is delicious stewed until tender in this sauce; small potatoes, white sweet potatoes, yuca or taro root/malanga (peeled or not, cut in chunks, cooked in salted water until tender) are delicious added to that stew. The same can be done with boneless, skinless chicken thighs. As mentioned above, the sauce is really delicious with grilled pork loin, chicken breasts or thighs, even quail and duck breasts (or whole roasted duck). Thinned out, the sauce can be used to make Chilaquiles (LINK) or to sauce Enchiladas (LINK). Both preparations are best with crema or melted cheese to balance the muscle of the sauce.
For the professional: The sauce makes about 2 cups and can be easily scaled. By weight, for every two parts dried chile, use 3 parts onion and garlic. Flavorings can go toward sweet (cinnamon, clove, black pepper) or savory (cumin, Mexican oregano, black pepper). Fruit like the orange called for is a delicious addition, but others are welcome. For me, a little vinegar is a must to create balance.