Instant Pot Pot Roast

Rub roast all over with salt and pepper. Select SAUTÉ setting on a programmable pressure multicooker (such as Instant Pot). (Times, instructions, and settings may vary according to cooker brand or model.) Select HIGH temperature setting, and allow to preheat 2 to 3 minutes. Add oil and roast to cooker. Cook, undisturbed, until browned on 4 sides, 4 to 5 minutes per side. Transfer roast to a plate; set aside.

Add onions, carrots, garlic, thyme sprigs, and bay leaf to drippings in cooker. Cook on HIGH, stirring often, until coated in browned bits, 1 to 2 minutes. Add Madeira; cook, undisturbed, until slightly reduced, about 1 minute. Press CANCEL.

Whisk together tomato paste, mustard, and 1 3/4 cups of the broth in a small bowl. Place roast over vegetable mixture in cooker; pour broth mixture over roast. Scatter potatoes evenly on top. Cover cooker with lid, and lock in place. Turn steam release handle to SEALING position. Select MANUAL/PRESSURE COOK setting. Select HIGH pressure for 75 minutes, or 25 minutes per lb. (It will take 10 to 15 minutes for cooker to come up to pressure before cooking begins.)

When cooking has finished, let the pressure release naturally for 10 minutes. Carefully turn steam release handle to VENTING position, and let steam fully escape (float valve will drop). (This will take 3 to 5 minutes.) Remove lid from cooker.

Carefully transfer roast to a cutting board; let rest 10 minutes. Meanwhile, transfer vegetable mixture to a large platter using a slotted spoon. Remove and discard thyme sprigs and bay leaf. Select SAUTÉ setting on cooker; select HIGH temperature setting, and bring broth mixture to a boil. Boil, undisturbed, until reduced by half, about 10 minutes. Whisk together cornstarch and remaining 1/4 cup broth in a small bowl until smooth. Slowly drizzle cornstarch mixture into broth mixture in cooker, whisking constantly, until sauce is thickened, about 1 minute. Press CANCEL. Stir in vinegar. Arrange roast alongside vegetable mixture on platter. Garnish with additional thyme sprigs, and serve alongside sauce.