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, browning each side for 45 seconds. Transfer to slow cooker.

Reduce heat to medium and melt 1 tablespoon of butter. Add onions and cook for 5 minutes. Add garlic and cook for 1 minute. Add a splash of wine and loosen the brown bits in the skillet. Transfer to the slow cooker.

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

Cook on low for 7 ? to 8 hours or high for 3? 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, combine ? cup cold water with 3 tablespoons corn starch. Slowly add to the stew, stirring to incorporate.

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