When I made my prime rib roast for the first time, I bought it pre-seasoned from Costco. (So yes, I cheated), but here’s the directions I followed to make sure my prime rib roast would come out exactly the way I like all my steaks cooked; medium rare.
- Pre-seasoned prime rib roast from Costco (mine weighed 7lbs)
- 5 carrots
- 4 onions (any, I bought a bag of mixed onions and used 2 yellow, 1 white and 1 purple/red)
- 1/4 cup Beef Stock
- 1 teaspoon of Corn starch/flour
- 1 tablespoon of Worcestershire sauce
- 1 teaspoon salt
- 1 tablespoon black pepper
- 1 tablespoon sugar
- Pre-heat your oven on BROIL to 500 degrees Fahrenheit.
- Peel the carrots & onions. Cutting them to fit UNDER your prime rib roast steadily.
- When your oven is ready, place your prime rib roast. Let it cook for 5 minutes PER pound!
- After time is up, DO NOT OPEN YOUR OVEN DOOR!!! This is the most important thing to NOT do.
- Turn off the heat for your oven & let it sit in there for TWO hours. Remember.. do NOT.. I repeat, DO NOT open your oven door until the timer’s completely up,
- After letting it sit for 2 hrs in the oven unbothered, remove it from the oven & remove the prime rib roast from the roasting pan/rack onto a cutting board. Remove the vegetables as well, you’re going to save and use the drippings for the au jus (sauce).
- If your roasting pan can handle direct heat from your stove, use it to make the au jus, if not, just transfer the drippings to a pan.
- Turn the heat on your stove to medium-high. When simmering, add a teaspoon of cornstarch or flour (whichever works fine) and mix it well. Make sure there aren’t any clumps.
- Add the beef stock and let it come to a boil.
- Add worcestershire sauce (optional, I just personally think it adds more flavor to the au jus and I just like using it with most of my steaks)
- Add salt, black pepper and sugar. I recommend seasoning with these ingredients to your personal liking, so taste testing as you make this sauce is highly recommended.
- Also, if you prefer your sauce thicker & gravy-like, feel free to add a little more corn starch or flour. No more than ½ a teaspoon more though.