You first need to rehydrate and soften all the dried chilies. So, put the chilies in a bowl and cover them completely with boiling water. Let the chilies sit in the water for 30 minutes, then tip them into a fine-meshed sieve to drain, and discard the water.

Remove any of the chilies’ stalks — the ancho chilies usually come with their stalks still attached. Now add the chilies — seeds and all — to your food processor, together with all the adobo’s remaining ingredients — the garlic, cumin, cloves, cinnamon, vinegar, black pepper, and salt.

Give the mix a good blitzing until you have a uniformly smooth paste. That took me about 2 minutes with the processor running on high. That’s it. Adobo done. Time now to prep the lamb.

Use a small, sharp, finely-pointed knife to make 4, down-to-the-bone, width-wise cuts into either side of the lamb — that’s 8 cuts in total. Start and end the cuts 1 ½ inches from the sides of the leg, and take some care not to cut all the way through the meat.

Transfer the lamb to a good size mixing bowl, and pour the adobo paste over it. Now use your fingers to work the adobo into the cuts in the lamb. Then spread the remaining paste as evenly as you can all over the outside of the lamb. Now set the bowl in your refrigerator so the lamb marinates overnight in its adobo coating.

Set your oven to 350F / 180C.

Place the onion domes in the Dutch oven. Arrange them so they’ll act as supports for the lamb. Now set the adobo-coated lamb on top of the onions. As much as possible, you’re aiming for those onion domes to hold the lamb above the bottom of the Dutch oven.

Cover the top of the unlidded Dutch oven with heavy foil. Use enough so that it overlaps the top by two inches. Press the Dutch oven’s lid down onto the foil, and then use your fingers to crimp the foil into a good, tight seal all around that big pot’s top edges.

Now set the sealed pot on a middle shelf in the heated oven, and let it cook for 4 undisturbed hours.

Once the 4 hours is up, turn off the oven, remove your big pot, and let it sit and cool for fifteen minutes or so. While that’s happening, you can start giving the cherry tomatoes a good charring (next step.)

Set a big heavy skillet — I used a deep-sided, 12 inch one — on a high heat, and add one tablespoon olive oil. As the oil is just starting to smoke a little, add half the cherry tomatoes. Let them sit on that high heat for about 4 minutes. You’ll find the tomatoes flatten slightly with all that heat on their undersides — that’s grand. Now give them a stirring turn to expose their upper sides to that charring heat. Let them run for another 4 minutes, and then turn them into a bowl. Now repeat the charring process for the rest of the tomatoes.

Once the Dutch oven has had its fifteen minutes’ cooling, remove the top and the foil. Carefully lift out the lamb and set it aside on a plate. You’ll probably find the lamb still has some of its adobo coating. That’s fine — it’ll get mixed with the lamb when you break it apart into chunks once you’ve finished making the sauce. Return the plated lamb to your still-warm oven — it’ll keep nicely hot in there while you complete your sauce.

Use a slotted spoon to remove the halved onions, and tip them into your food processor. Blitz them smooth, and pour them back into your Dutch oven with all its cooking juices from the lamb. Set the Dutch oven over a medium heat and stir in the water and oregano.

As soon as the sauce starts gently bubbling, turn off the heat. Now’s the time to check it for saltiness — adjust according to your taste.

If you feel the sauce is too thick — I like mine to be the consistency of a good variety of canned tomato soup — add a little more water.

Like it said on the pack, I heated these for about 60 seconds each side in a dry skillet set on a high heat. Stack the heated tortillas on a serving plate and cover them with a cloth to keep them softly warm.

Set your sauce onto a medium heat to bring it almost to the boil — so it’s ready for serving. While that’s happening, take the lamb from the oven and place it in a good-looking serving dish. I used a warmed, 14-inch, cast-iron gratin dish.

Now use a pair of forks to quickly pull the lamb apart into bite-size chunks — but don’t shred it into long stringy pieces. Bite-size chunks — albeit a little raggedy around the edges — are what you’re aiming for here. If you find any tough, sinewy bits, cut them away and discard them. I then pick out any particularly well-fatted pieces, chop them finely, and mix them back into the chunks of lamb — after all, fat is flavor.

Pour the nicely hot sauce into an ample serving bowl, and present it on your table alongside the dish of lamb, and the plated tortillas. Offer the quartered limes and chopped cilantro in little bowls for self-service.

Let folks ladle the sauce into their bowls — about ¾ full is grand. They can then top their birria sauce with a polite helping of lamb.

Eat with soup spoons and meat-corralling pieces of tortillas. For me, a good squeeze of lime over the lamb, and a little garnishing cilantro is just dandy — muchas gracias!