Step 1: Prepare and Season the Meat

Cut the stew meat into 1-inch cubes, trimming off any large pieces of fat (but leaving marbled fat is fine).

Season the beef cubes with black pepper, garlic salt, and celery salt. Toss to evenly coat the meat.

Sprinkle flour over the seasoned beef, tossing again to ensure it’s evenly distributed.

Step 2: Sear the Meat

Heat 3 tablespoons of olive oil in a large skillet over medium-high heat.

Add the beef cubes in batches to avoid overcrowding the pan. Brown each side for about 45 seconds, adding more oil if necessary.

Once browned, transfer the meat to the slow cooker.

Step 3: Sauté the Onions and Deglaze the Pan

Reduce heat to medium and melt 1 tablespoon of butter in the same skillet.

Add chopped onions and cook for about 5 minutes until they are soft and translucent.

Stir in minced garlic and cook for an additional minute until fragrant.

Add a splash of grape juice to the pan and deglaze, scraping up any brown bits stuck to the skillet.

Transfer the onion and garlic mixture to the slow cooker.

Step 4: Cook the Stew

Add all remaining ingredients, except the peas, cornstarch mixture, and 2 tablespoons of cold butter, into the slow cooker.

Stir to combine.

Cover and cook on low for 7½ to 8 hours, or on high for 3½ to 4 hours, until the vegetables are softened and the potatoes are fork-tender.

Step 5: Add Final Ingredients and Thicken

In the last 15 minutes of cooking, add the frozen peas.

Remove any bay leaves and the rosemary sprig.

For a thicker stew, combine ¼ cup cold water with 3 tablespoons cornstarch to make a slurry. Slowly add this to the stew while stirring, and let it thicken.

Step 6: Finish and Serve

Turn off the heat once the stew has reached the desired consistency.

Swirl in 2 tablespoons of cold butter for a smooth, velvety finish (a technique known as Monter au Beurre).

Optionally, add 3 drops of Gravy Master for a richer color.

Serve the stew hot and enjoy!