Bourguignon Style Pot Roast 6 Steps
Bring a medium pot of water to a boil and blanch the cippolini or pearl onions for 2 minutes, use a spider to remove and peel skins off. Cut any onions that are larger than 1 ½ inches in diameter right in half. Peel and cut the carrot into chunks approximately 1-inch in size and blanch the chunked carrots in the same pot of water for 4 minutes, then strain from the water and set aside with the peeled onions.
Remove the sirloin roast from refrigeration at least 30 minutes prior to cooking. Use paper towels to wipe down any excess moisture and make 6 small incisions in and around the roast, push a garlic clove deep into each incision. Season all around the roast liberally with kosher salt as well as black pepper. Heat a cast iron pan on high heat and put just enough vegetable oil to lightly coat the bottom of the pan. Begin searing the seasoned roast on all sides, approximately 1-1 ½ minutes per side until browned.
While the roast is being seared, toss the blanched and peeled cipollini onions, blanched carrots, mushrooms and thyme sprigs with a splash of olive oil and a light seasoning of salt and pepper and arrange in a roasting pan and top with a roasting rack.
Place the seared roast on top of the rack in the roasting pan making sure that the beef is not touching the vegetables underneath. Roast in a preheated 350°F oven until a meat thermometer reads 130°F internal temperature (the roast is technically rare at this point but will continue to cook while resting and reach medium rare). This may take 1-1.5 hours depending on the size of your roast and the strength of your oven. A good general rule of thumb is 25 minutes per pound of beef. Remove the roast from the roasting pan, tent and allow to rest.
While the roast is resting, transfer the roasting pan with the vegetables to the stove top and heat on medium. Add in the tomato paste, grainy mustard, all-purpose flour and stir until even. Continue to cook on the heat for 1-2 minutes until it begins to stick on the bottom of the pan. Deglaze with the red wine and scrape up any and all brown bits from the bottom. Continue to cook until most of the wine has reduced. Add in the beef broth and bring to a simmer once again. Adjust seasoning with salt and pepper, keep warm and set aside.
Once the roast has a chance to rest, slice 1/2-inch thick slices and arrange on a serving platter, top with the roasted vegetable sauce mix as well as a light sprinkle of flaky sea salt, and serve immediately.