Rinse, then pat the corned beef dry with a paper towel.
Set a large skillet on the stove top to medium-high heat. Add cooking oil to coat the bottom of the pan. When the oil is hot, brown the meat on all sides.
Place the browned corned beef into the slow cooker.
In a small bowl mix together the maple syrup, mustard, pepper, and garlic clove. Pour this sauce over the corned beef in the slow cooker.
Cover and cook and LOW for 7 hours, without opening the lid during the cooking time.
Serve with desired sides, I made mashed red potatoes, steamed carrots and cabbage.