The day before you want to serve the ribs, put the meat in a baking dish or other large container and soak it with 2 bottles of the Guinness. Cover the ribs with plastic wrap, and let them marinate in the fridge for 12 to 24 hours, turning them over at the halfway mark to make sure everything gets evenly beered up. (The longer you marinate the meat, the beerier — and better — it will be.)

Take the ribs out of the fridge and let them sit on the countertop for about an hour, until they come up to room temperature.

Meanwhile, preheat the oven to 400°F.

Pull the ribs out of the beer, pat them dry with a paper towel, and season them generously on all sides with the salt and pepper.

Heat the corn oil in a very large ovenproof pot or casserole with a tight-fitting lid over medium-high heat. When the oil is smoking, put the short ribs in the pot. Let the meat cook, turning each piece every couple of minutes with a pair of tongs, for about 8 minutes, until the ribs are chocolate-brown and caramelized on all sides, like a good steak (they should smell like a good steak, too). This is a smoky process, so you might want to open a window or two before you start (and maybe think about pulling the battery out of that smoke alarm).

Use a pair of tongs to pull the ribs out of the pot and put them on a plate. Then pour the oil out of the pot and use a paper towel to wipe down the insides, so the caramelized stuff doesn’t burn and flavor everything.

Add the tomato paste and mix it in well, so the vegetables are coated in the paste. Let the mixture cook for about 30 seconds, until you can smell the tomato caramelizing.

Add the flour, mix it in and let it toast for about 30 seconds, being careful not to let it burn on the bottom of the pot.

Add the red wine and scrape the bottom of the pot to release the fond (the base of the sauce — the good stuff that’s caramelized down there). Then add the thyme and bay leaves.

Raise the heat to high and let the sauce cook for about 5 minutes, until it thickens up and the wine has reduced by three quarters. This is a good time to wipe down the sides of the pot above the cooking mixture with a wet cloth, so that anything that’s splashed onto the sides doesn’t burn and fall into the sauce, wrecking the flavor.

When the sauce is a thick chocolate color, pile the ribs back into the pot. Add the beef broth and 2 cups of water, so the short ribs are submerged in the liquid. Give everything a stir to bring it together, wipe down the sides of the pot again, and bring the mixture to a boil.

Cover the pot and put it on the middle oven rack. Cook the ribs for 2 1/2 to 3 hours, turning them every hour. They’re ready when they’re fork-tender.

Heat the corn oil in a medium-sized saucepan over high heat. Add the onions, stirring them around and shaking the pan so they’re coated in the oil. Cook the onions for about 1 minute, until you start to get a little caramelization. Then turn the heat down to medium and keep cooking for about 5 minutes, until the onions are golden brown.

Add the salt and pepper and 1 1/2 cups of water. Stir to combine everything, and continue cooking for about 10 more minutes, until the onions are very soft and all the sharpness has gone out of their flavor.

Pour everything in the pan — onions and liquid — into a blender, and blend (starting on low speed and working your way up) for about 30 seconds, until everything’s liquified. Pour the onion purée into a bowl and set it aside.

Pull the meat from the pot with tongs, and pile it on a serving platter.

Strain the cooking juices into a medium-sized saucepan. You’ll end up with a thick mush in the strainer: take a spoon and push everything through so you get all the good stuff.

Add the last 1/2 cup of Guinness and the onion puree to the saucepan, and stir everything together; if the sauce has cooled down, warm it up over medium heat.

Pour the sauce over the short ribs. Sprinkle the celery leaves on top, and serve the ribs right away — with more Guinness, of course.