Cast-Iron Skillet Prime Rib Roast and Gravy

Preheat oven to 275 degrees F (135 degrees C). (Prep time: 5 minutes)

Generously season the prime rib roast with coarse sea salt and freshly ground black pepper. Ensure an even coating for optimal flavor. (Prep time: 2 minutes)

Heat a large cast-iron skillet over medium-high heat until smoking hot. Sear the roast on all sides, creating a beautiful crust. Aim for 2-3 minutes per side. (Cook time: 8-12 minutes)

Position the roast with the ribs facing up in the skillet. Transfer to the preheated oven. Roast for 45 minutes. (Cook time: 45 minutes)

Scatter the quartered onion around the roast. Continue cooking until an instant-read meat thermometer inserted into the thickest part of the meat registers 130 degrees F (54 degrees C) for rare, approximately 2 more hours. Adjust cooking time based on desired doneness. (Cook time: ~2 hours)

Remove the roast from the skillet. Wrap tightly in aluminum foil and let rest for 15-20 minutes. This allows the juices to redistribute, resulting in a more tender and flavorful roast. Leave the onion pieces in the skillet. (Rest time: 15-20 minutes)

Carefully pour the drippings from the skillet into a bowl. Skim off excess grease, reserving the flavorful drippings. (Prep time: 5 minutes)

Return the degreased drippings to the skillet with the onion pieces. Place over medium heat and melt the butter into the drippings. (Prep time: 2 minutes)

Whisk in the flour to create a roux. Cook for 1-2 minutes, stirring constantly, until the roux is smooth and lightly golden. (Cook time: 1-2 minutes)

Gradually stir in the red wine, scraping up any browned bits from the bottom of the skillet. Cook until the wine is mostly absorbed. (Cook time: 2 minutes)

Gradually whisk in the beef stock until the gravy is smooth. Stir in the fresh thyme sprigs. (Prep time: 2 minutes)

Reduce heat to low and simmer the gravy until thickened to your desired consistency, approximately 5-8 minutes. (Cook time: 5-8 minutes)

Strain the gravy through a fine-mesh sieve to remove the onion pieces and thyme sprigs. Discard the solids. (Prep time: 3 minutes)

Slice the prime rib against the grain and serve immediately, generously drizzled with the homemade gravy.