Make-Ahead Shepherd's Pie | America's Test Kitchen

Ingredients

• 2 tablespoons unsalted butter
• 1 large onion, chopped fine
• 2 pounds 85 percent lean ground beef
• Salt and pepper
• 5 tablespoons all-purpose flour
• 2 tablespoons tomato paste
• 3 cups low-sodium chicken broth
• 1/4 cup heavy cream
• 2 tablespoons Worcestershire sauce
• 1 tablespoon minced fresh thyme
• 1 (1-pound) bag frozen peas and carrots
• 2 1/2 pounds red potatoes, peeled and cut into 2-inch pieces
• 6 tablespoons unsalted butter, melted
• 2 tablespoons cream cheese