Cut meat into 1-inch cubes, discarding any large pieces of fat.

Sprinkle beef with black pepper, garlic salt, and celery salt. Toss to coat. Sprinkle flour over the meat and toss again.

Heat 3 tablespoons olive oil in a large skillet over medium-high heat. Add the meat in batches, brown on each side for 45 seconds. Transfer to slow cooker.

Reduce heat to medium and melt 1 tablespoon butter. Add onions and cook for 5 minutes. Add garlic and cook for 1 minute. Deglaze with a splash of wine. Transfer onion mixture to the slow cooker.

Add all remaining ingredients except for peas, corn starch mixture, and 2 tablespoons cold butter.

Cook on low for 7 ½ to 8 hours or high for 3½ to 4 hours, until vegetables are softened and potatoes are fork tender.

Add peas during the last 15 minutes of cooking. Remove bay leaves and rosemary stem.

Optional: To thicken, combine cold water with corn starch and slowly add it to the stew, stirring to incorporate.

Turn off the heat and swirl in 2 tablespoons of cold butter for a smooth finish. Optional: Add drops of Gravy Master for darker color.