Porcini Dusted Prime Rib with Mushroom-Shallot Reduction

By: David Bonom

A roast this spectacular should be handled and seasoned with the thoughtfulness it deserves. But fear not— as long as you use a meat thermometer, cooking this umami-bomb of a meal is all but mistake proof.

The sauce may be made a day ahead and kept refrigerated: simply warm it in a small saucepan before serving. The roast itself couldn’t be simpler—or more incredibly flavorful.

To enhance the savory meat—without detracting from its inherent rich flavor-- grind dry porcinis and rub the resulting fine dust onto the meat to form a crust. Throw onion wedges and fingerling potatoes (any combination of red, purple and yellow) around the meat: as they cook together, the potatoes absorb the meat juices and porcini, making them an incredibly flavorful “built in” side dish.



Prime Rib and Potatoes

  • 5-6 pound SRF American Wagyu boneless prime rib Buy Now
  • 1/2 ounce dried porcini mushrooms
  • 2 1/2 teaspoons sea salt, divided
  • 1 teaspoon freshly ground black pepper, divided
  • 3 pounds assorted fingerling potatoes
  • 3 medium red onions, cut through the root into 8 wedges each
  • 2 tablespoons extra virgin olive oil

Mushroom-Shallot Reduction

  • 1/2 pound dried porcini mushrooms
  • 4 tablespoons unsalted butter, divided
  • 2 tablespoons extra virgin olive oil
  • 1 pound sliced white mushrooms
  • 1/2 pound shiitake mushrooms, stemmed and sliced
  • 1 cup thinly sliced shallots
  • 1 1/2 teaspoons fresh thyme leaves
  • 1/2 teaspoon sea salt
  • 2 cup chicken stock or low sodium chicken broth
  • 1/4 cup madeira
  • 1/4 teaspoon freshly ground black pepper

Prime Rib and Potatoes

For the roast, pulse the porcini mushrooms in a spice grinder a few times until they become a mixture of small pieces and dust. Transfer to a bowl and combine with 1 3/4 teaspoons of the salt and 3/4 teaspoon of the pepper.
Rub the mixture over the entire rib roast and transfer it to an oiled rimmed baking sheet.
Combine the potatoes, onion wedges, oil and the remaining 3/4 teaspoon salt and 1/4 teaspoon pepper in a bowl; toss gently to coat. Arrange vegetables on the baking sheet around the roast and let stand at room temperature for 20 minutes.
Preheat the oven to 350°F.
Cook the rib roast until and instant read thermometer inserted into the thickest portion of the meat registers 115°F, about 1 hour 45 to 1 hour 50 minutes.
Remove from the oven and loosely tent with aluminum foil; let rest 25-30 minutes before slicing.
While the roast cooks make the Mushroom-Shallot Reduction.

Mushroom-Shallot Reduction

Soak the dried porcini mushrooms in 1 1/2 cups of hot water until softened, about 20 minutes. Transfer the porcini mushrooms to a cutting board with a slotted spoon and coarsely chop them. Reserve 1/2 cup of the porcini soaking liquid.  
Melt 2 tablespoons of the butter with the oil in a large skillet over medium-high heat.
Add the white mushrooms, shiitake mushrooms, shallots, thyme and salt; cook, stirring occasionally, until the mushrooms just start to brown, about 9-10 minutes.
Stir in the porcini mushrooms and cook, stirring, 1 minute.
Add the madeira and reserved porcini liquid, bring to a boil and cook until the liquid is absorbed, about 1 1/2- 2 minutes.
Pour in the chicken stock, bring to a boil and cook until the liquid is slightly thickened, about 6 minutes. Remove from the heat and add the remaining 2 tablespoons butter, stirring constantly, until melted. Season with the pepper and serve over the sliced rib roast.