Tori Spellings Shepherds Pie

Name: Tori Spelling's Shepherd's Pie
Ingredients: 3 lb. Yukon gold potatoes, peeled and quartered lengthwise; 1 tsp. kosher salt + extra for seasoning; 2 tbsp. butter; 1/2 c. milk; 1 c. sour cream; Freshly ground black pepper; 1–1 1/2 lb. ground beef (can substitute lamb or turkey); 1 small onion, chopped; 2 garlic cloves, minced; 1 can beef gravy; 1/4 tsp. Worcestershire sauce; kosher salt; 1 c. fresh or frozen baby green peas; 1/4 tbsp. butter; 2 1/2 c. Mashed potatoes