Step 1

Pat the sirloin tip roast dry with paper towels to ensure a good sear. Season the entire roast generously on all sides with kosher salt and black pepper.

Step 2

Heat 2 tablespoons of vegetable oil in a large skillet over medium-high heat. Once the oil is hot, add the whole sirloin tip roast and sear on all sides until it develops a deep brown crust, about 3 to 4 minutes per side. Remove the seared roast from the pan and set aside.

Step 3

In the same skillet, reduce the heat to medium and add the garlic. Stir frequently, cooking until the garlic becomes fragrant and lightly browned, about 1 minute. Be careful not to burn it.

Step 4

Carefully pour in the sherry (or dry wine) to deglaze the pan, using a wooden spoon to scrape up any browned bits stuck to the bottom. Let the mixture simmer for 2-3 minutes to reduce slightly.

Step 5

After removing the pan from the heat, stir in the red wine vinegar, soy sauce, and Worcestershire sauce into the sherry mixture. Season with salt and pepper and mix well to combine all the flavors.

Step 6

Add the onion wedges and carrot chunks to the bottom of the slow cooker, spreading them out evenly. Lay the raw bacon strips and seared sirloin tip roast on the vegetables. Pour the sherry-garlic mixture over the beef.

Step 7

Toss in the thyme sprigs (or dried herbs), bay leaf, and the parsley stems. Cover the slow cooker and cook on low heat for 6 to 8 hours or until the roast is tender and easily pulls apart with a fork. For a firmer texture, cook until it reaches an internal temperature of about 190°F.

Step 8

Once cooking is done, carefully remove the whole roast, onions, carrots, bacon, and herbs from the slow cooker. Discard the bacon, bay leaf and herbs.

Step 9

If you'd like a thicker sauce, strain the liquid from the slow cooker into a saucepan on the stove. Create a roux by combining 3 tablespoons of unsalted butter with 3 tablespoons of flour in the saucepan over medium heat. Slowly whisk in the cooking liquid, stirring constantly, until the sauce thickens to your desired consistency. This may take about 3-5 minutes. Stir in the parsley leaves at the end.

Step 10

Taste for seasoning, add more salt as needed, and a splash of vinegar to brighten the flavors.

Step 11

Slice or shred the roast and serve with the carrots and onions, drizzling the rich gravy over the meat. Enjoy your favorite sides!