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Slow Cooker Garlic Onion Beef Roast


  • Author: Grace

Ingredients

Scale

Here’s a breakdown of what goes into this comforting beef roast and why each ingredient plays an important role.

For the Beef Roast

  • 34 lb chuck roast — This well-marbled cut is ideal for slow cooking, as its connective tissue breaks down over time to create incredibly tender, juicy meat.
  • 2 tbsp olive oil — Used for searing the roast to develop a deep, flavorful crust before slow cooking.
  • 2 large yellow onions, thickly sliced — These caramelize slowly throughout the cooking process, adding natural sweetness and depth to the gravy.
  • 8 cloves garlic, smashed — Infuses the entire dish with rich, roasted garlic flavor as it slowly cooks alongside the beef.
  • 2 cups beef broth — Forms the flavorful liquid base that becomes the rich gravy.
  • 1 tbsp Worcestershire sauce — Adds deep umami flavor and a subtle tang.
  • 1 tbsp Dijon mustard — Contributes a subtle sharpness that balances the richness of the beef.
  • 2 tbsp tomato paste — Adds body and a slightly sweet, concentrated tomato flavor to the gravy.
  • 1 tbsp soy sauce — Deepens the savory, umami notes throughout the dish.

Seasonings

  • 2 tsp kosher salt — Essential for properly seasoning the beef and enhancing every other flavor.
  • 1 tsp freshly ground black pepper — Adds a subtle, warm bite.
  • 1 tsp garlic powder — Reinforces the garlic flavor alongside the fresh smashed cloves.
  • 1 tsp onion powder — Adds an extra layer of savory onion flavor.
  • 1 tsp smoked paprika — Contributes a warm, smoky undertone to the seasoning blend.
  • 1 tsp dried thyme — A classic herb that pairs beautifully with slow-cooked beef.
  • 1 tsp dried rosemary — Adds an earthy, aromatic quality typical of hearty beef dishes.
  • 1 tsp dried parsley — Adds a mild, fresh herbal note.
  • 2 bay leaves — Infuses the cooking liquid with subtle, aromatic depth throughout the long cooking process.

Optional Add-Ins

This recipe is easy to turn into a complete one-pot meal with the addition of vegetables and other flavor boosters:

  • 1 lb baby Yukon Gold potatoes (for a hearty, starchy addition)
  • 4 large carrots, cut into chunks (for natural sweetness and texture)
  • 8 oz mushrooms (for an earthy, umami-rich addition)
  • 2 celery stalks, chopped (for classic pot roast flavor)
  • 1 tbsp balsamic vinegar (for a touch of tangy depth)
  • Fresh thyme sprigs (for a more intense, fresh herbal flavor)
  • Crushed red pepper flakes (for a subtle kick of heat)


Instructions

This recipe requires just a bit of prep work before the slow cooker takes over. Here’s exactly how to make it.

Step 1: Pat the Roast Dry

Pat the chuck roast dry with paper towels. Removing excess moisture helps achieve a deep, flavorful sear in the next step.

Step 2: Season the Roast

Season all sides of the roast generously with the kosher salt, black pepper, garlic powder, onion powder, smoked paprika, thyme, rosemary, and parsley, making sure to coat every surface evenly.

Step 3: Sear the Roast

Heat the olive oil in a large skillet over medium-high heat. Sear the roast for 3–4 minutes per side until deeply browned on all sides. This step is essential for building a rich, caramelized flavor base that carries through the entire dish.

Step 4: Layer the Onions and Garlic

Arrange the sliced onions and smashed garlic in the bottom of a 6- to 8-quart slow cooker. These will cook down slowly, becoming sweet, soft, and packed with flavor.

Step 5: Add the Roast

Place the seared roast directly on top of the bed of onions and garlic in the slow cooker.

Step 6: Prepare the Braising Liquid

In a bowl, whisk together the beef broth, Worcestershire sauce, Dijon mustard, tomato paste, and soy sauce until fully combined.

Step 7: Pour and Add Bay Leaves

Pour the braising liquid mixture around the roast, then add the bay leaves to the slow cooker.

Step 8: Add Vegetables (Optional)

If using potatoes, carrots, mushrooms, or celery, arrange them around the roast in the slow cooker.

Step 9: Cook Low and Slow

Cover and cook on LOW for 8–9 hours or HIGH for 5–6 hours, until the beef is fork-tender and easily shreds apart.

Step 10: Rest the Roast

Remove the roast from the slow cooker and let it rest for 10 minutes before slicing or shredding. This resting period allows the juices to redistribute throughout the meat.

Step 11: Discard Bay Leaves and Finish the Gravy

Discard the bay leaves from the cooking liquid. For a thicker gravy, transfer the liquid to a saucepan and simmer for 5–10 minutes, or whisk in a slurry made from 1 tablespoon cornstarch mixed with 2 tablespoons cold water and cook until thickened.

Step 12: Serve

Serve the beef alongside the onions, garlic, vegetables, and plenty of rich gravy spooned over the top.