Position oven rack low in the oven, heat oven to 325°(see Instant-Pot instructions in NOTES). Trim beef ribs of excess outer fat, careful to leave meat attached to the bone. Dry meat with paper towels; sprinkle with salt and pepper, and dust lightly with flour on all sides.
In a large Dutch oven or oven safe pot with a secure lid, heat the oil over med heat. Sear the ribs on all sides, adding more olive oil as needed. Reserve browned ribs on a platter.
Add onion, celery, carrots, mushrooms, red pepper, and garlic to the pot and cook until softened. Season with salt and pepper. Stir in the bay leaves, thyme, and parsley. Raise the heat and add the wine to deglaze the pan.
Return the ribs to the pot and add the stock, and tomatoes. Stir to incorporate and make sure the meat is mostly covered. Bring it to a simmer, and drizzle with a little olive oil. Secure a lid on the pot and place in the preheated oven; cook for 4-41/2 hours.
Optional: Once ribs are fall-apart tender, remove from the oven and turn oven off. If desired, carefully skim any pools of fat on the top with a spoon and discard.
Taste and add more salt and pepper, as needed. Stir-in couscous, replace lid and return to the oven (still off), for 10-15 minutes.
Serve over Mashed Cauliflower (as shown) with a side of skillet-seared asparagus.
Notes
NOTE: It is important to use dry Marsala wine for this recipe rather than sweet Marsala.
Instant Pot Instructions:
STEP 1—Trim beef ribs of excess outer fat, careful to leave meat attached to the bone. Dry meat with paper towels; sprinkle with salt and pepper, and dust lightly with flour on all sides.STEP 2—Set Instant Pot to saute (high) and heat the oil to brown the ribs on all sides, adding more olive oil as needed. Work in batches to not overcrowd the pot so the meat will brown and not steam. Reserve browned ribs on a platter.STEP 3—Add onion, celery, carrots, mushrooms, red pepper, and garlic to the pot and saute until softened. Season with salt and pepper. Stir in the bay leaves, thyme, and parsley. Add 1/2 cup of wine to deglaze the pan. NOTE: Less liquid is needed when pressure cooking, so the amount of wine and stock is reduced by half from what is indicated in the original recipe card.STEP 4—Return the ribs to the pot and add 1 cup beef stock, and tomatoes. Stir to incorporate and make sure the meat is mostly covered. Set Instant Pot to High Pressure for 45 minutes. (It will take 15-20 minutes for it to come to pressure.)STEP 5—Allow the pot to naturally (slowly) release pressure for 10 minutes, then turn the steamrelease handle on the top of the lid from the “sealed” position to the “venting” position to complete the release.STEP 6—Remove the lid and stir in the Israeli couscous. Return the lid to seal in the steam (do not turn the pot on again) and let the pot sit for 10 minutes to allow the couscous to absorb the liquid and cook.When the couscous is softened, taste the stew and add salt or pepper, as needed before serving.