Blue Cheese Burgers

Here's a departure from the plain old hamburger.

• 1-1/2 pounds lean ground beef
• 1 tablespoon Worcestershire sauce
• 1/2 teaspoon garlic salt
• 1/4 teaspoon ground black pepper
• 1 3-ounce package cream cheese, softened
• 3 tablespoons crumbled blue cheese
• 1 tablespoon Dijon mustard