1 Prepare the brisket: Rinse the brisket and pat it dry with paper towels. If your brisket has more than 1/4-inch layer of fat, trim off the excess. Season it on both sides with 1 teaspoon of the salt and the ground pepper.
2 Sear the brisket: Select the “Sauté” program on your pressure cooker, adjust it to its highest heat setting, and add the oil to the pot. (If you are using a stovetop pressure cooker, heat the oil over medium high heat.)
Use a pair of tongs to lower the brisket into the pot with the side with the most fat facing down, and let it sear for 6 minutes. Turn it over and sear it for 6 more minutes. Both sides should be a rich, dark brown color.
Transfer the seared brisket to a plate.
3 Cook the onions and garlic: Adjust your pressure cooker to its medium “Sauté” setting. (If you are using a stovetop pressure cooker, lower the heat to medium.) There should be plenty of fat left in the pan after searing the brisket; if not, add another teaspoon or two of olive oil to cook the onions.
Add the onions, garlic, and the remaining 1/2 teaspoon of salt. Cook, stirring frequently, until the onions are soft and beginning to brown, about 10 minutes. Scrape the bottom of the pot as you stir the onions to help release all of the browned bits from the bottom of the pot.
4 Stir the water, wine, ketchup, and spices into the onions and garlic.
5 Cook the brisket: Use a pair of tongs to lower the seared brisket back into the pressure cooker, with the side with the most fat facing up. Place the lid on your pressure cooker. Make sure that the pressure regulator is set to the “Sealing” position.
Select the “Manual” program, then set the time to 50 minutes at high pressure. (For stovetop pressure cookers, cook for 45 minutes at high pressure.)
It will take about 10 minutes for your pressure cooker to come up to pressure, and then the actual cooking will begin. Total time from the time you seal the pressure cooker to the finished dish is about 60 minutes.
6 Release the pressure: You can either perform a quick pressure release by moving the vent from “Sealing” to “Venting,” or you can let the pot depressurize naturally (this takes about 20 minutes). (For stovetop pressure cookers, perform a quick pressure release.)
7 Separate the brisket, onions, and cooking liquid: Use tongs to transfer the brisket to a plate or carving board. Strain the cooking liquid into a fat separator, collecting the cooked onions and garlic in the strainer.
8 Make the gravy: Return the drained onions and garlic to the pressure cooker pot. Pour the cooking liquid from the fat separator back into the pot, discarding the fat that is left behind. (If you don’t have a fat separator, wait for the fat to rise to the top of the liquid, then skim off as much as you can.)
With an immersion blender, blend the cooking liquid, onions and garlic into a thick gravy. (Alternatively, transfer the liquid, onions, and garlic to a blender to puree. Don’t fill the blender more than halfway, and be careful of the steam when opening the blender pitcher.
9 To serve: Slice the brisket against the grain into thin (1/4-inch) slices. Pour the gravy over the brisket and serve hot.