Created by ssej1078 on October 15, 2018
Step 1: Cut your 1/2 rack of spare ribs into 2 or 3 pieces so all the ribs will fit in the pressure cooker.
Step 2: Sprinkle the ribs on both sides with the kosher salt and season with pepper.
Step 3: Pour the beef stock into the pressure cooker and place the steamer insert in the cooker.
Step 4: Place the ribs on the steamer insert.
Step 5: Rather than stacking sections of ribs, place the rib sections on end and sort of curl them around the pot so the pieces aren’t touching to ensure even cooking.
Step 6: Lock the lid in place and bring the pot to high pressure (15 psi for stove top or 9 to 11 psi for electric).
Step 7: If using a stove-top pressure cooker, maintain the pressure for 20 minutes for tender ribs
Step 8: Or, if you prefer that the ribs be falling-off-the-bone tender, cook for 30 minutes, adjusting the burner as necessary.
Step 9:
Step 10: If using an electric pressure cooker, such as an Instant Pot, cook at high pressure for 20 minutes for tender ribs or, if you prefer ribs that are falling-off-the-bone tender, cook for 30 to 25 minutes.
Step 11: When the timer goes off, turn the cooker off. Do not let the pressure cooker automatically switch to the “warm” setting.
Step 12: Use the natural method to release the pressure in the cooker. Unlock and remove the lid.
Step 13: Using tongs, transfer the ribs, bone-side up, to a rack placed on an aluminum foil-lined sheet pan.
Step 14: Let the cooking liquid in the pressure cooker rest for several minutes to allow the fat to rise to the surface.
Step 15: Meanwhile, preheat the broiler and adjust an oven rack to the top or second position.
Step 16: While the broiler heats, spoon off and discard the fat from the surface of the cooking liquid.
Step 17: Place the stove-top cooker over medium heat or turn the electric cooker to “brown” and bring the stock to a vigorous simmer.
Step 18: Cook until the stock is reduced to 1/3 of the original volume, 8 to 10 minutes.
Step 19: Stir in the mustard and brown sugar, and continue simmering for about 6 minutes more, or until the sauce resembles a thick syrup.
Step 20: Remove from the heat.
Step 21: Baste the bone side of the ribs with some of the mustard sauce.
Step 22: Slide the ribs under the broiler until the sauce is bubbling, about 4 minutes.
Step 23: Remove the sheet pan from the oven, turn the ribs over, and baste with the remaining glaze.
Step 24: Return to the broiler until warmed through, about 6 minutes.
Step 25: Cut the ribs into 1- or 2-rib sections and serve.