Shepherd's Pie

INGREDIENTS

• 1 teaspoon Worcestershire sauce
• 1/2 cup fresh or frozen corn kernels
• 2 teaspoons freshly chopped rosemary leaves
• 2 tablespoons canola oil
• 1 cup chicken broth
• 1 1/2 pounds russet potatoes
• 1 teaspoon kosher salt
• 2 carrots, peeled and diced small
• 1/4 teaspoon freshly ground black pepper
• 1/2 cup fresh or frozen English peas
• 2 ounces unsalted butter
• 1/2 teaspoon freshly ground black pepper
• 1/4 cup half-and-half
• 2 teaspoons tomato paste
• 1 egg yolk
• 2 cloves garlic, minced
• 1 teaspoon freshly chopped thyme leaves
• 2 tablespoons all-purpose flour
• 1 1/2 pounds ground lamb
• 3/4 teaspoon kosher salt
• 1 cup chopped onion