Corned Beef Shepards Pie With Horseradish Potatoes

Name: Corned Beef Shepards Pie With Horseradish Potatoes
Ingredients: Meat Filling:; 2 lbs. Grobbel’s Gourmet corned beef, cooked or raw; 1 onion, diced; 2 carrots, peeled and diced; 2 cloves garlic, minced; 2 tablespoons all-purpose flour; 1 tablespoon tomato paste; 1 cup corned beef cooking liquid or chicken stock; 1 tablespoon Worcestershire sauce; ½ cup frozen peas; Potatoes:; 2 lbs. Yukon Gold potatoes, skin and cut in half; ½ cup half-and-half; 3 oz unsalted butter; 1 egg; 1 tablespoon grated horseradish, or more to taste; Salt and pepper