Shepherd's Pie Soup

Bahan-bahan (8 porsi)

• 1 tablespoon olive oil
• 1 pound lean ground beef (or lamb)
• 1 large onion (diced)
• 3 cloves garlic (minced)
• 2 small potatoes (about 12 ounces, peeled and diced)
• 7 cups beef stock (divided)
• 1 teaspoon dried thyme leaves
• 1 teaspoon dried rosemary (crushed)
• 2 tablespoons tomato paste
• 1 bay leaf
• ½ teaspoon salt (or to taste)
• ½ teaspoon black pepper
• ¼ cup all-purpose flour
• 2 cups frozen peas and carrots
• 1 cup frozen corn kernels (thawed)
• 1 ½ pounds russet potatoes (about 3 small)
• 4 tablespoons butter (divided)
• ¼ cup heavy whipping cream
• 2 egg yolks
• salt and pepper to taste