Cut meat into 1-inch cubes and discard 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 and 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. Add a splash of wine and deglaze the pan. Transfer the onions/garlic mixture to the slow cooker.

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

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

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

Optional: To thicken, mix ¼ cup cold water with 3 tablespoons corn starch and slowly add it to the stew while stirring to incorporate.

Turn off the heat. Swirl in 2 tablespoons of cold butter for a smooth finish. Optional: Add 3 drops of Gravy Master for a darker color.