Swedish Meatballs

Name: Swedish Meatballs
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Cuisine: European
Ingredients: 1 pound ground beef; 1/4 cup panko bread crumbs; 1 tablespoon parsley, (chopped); 1/4 teaspoon ground allspice; 1/4 teaspoon ground nutmeg; ¼ cup onion, (finely chopped); ½ teaspoon garlic powder; ⅛ teaspoon pepper; ½ teaspoon salt; 1 egg; 1 tablespoon olive oil; 1 tablespoon butter; 4 tablespoons butter; 3 tablespoons flour; 2 cups beef broth; 1 cup heavy cream; 1 tablespoon Worcestershire sauce; 1 teaspoon Dijon mustard; Salt and pepper to taste