Beefed-Up Blue Cheese Burger | Best Health

Ingredients

• 6 oz cremini mushrooms (sliced)
• 12 oz extra-lean ground beef
• 1/2 small onion (finely minced and squeezed dry)
• 1 garlic clove (finely minced)
• 2 tsp Worcestershire sauce
• 1 small egg white
• 1/4 cup bread crumbs
• 2 tsp tomato puree
• 1 tsp fresh rosemary (finely minced)
• 3/4 tsp salt
• 1 tsp pepper
• 4 tbsp blue cheese (crumbled)
• 4 whole-grain buns (hollowed out on both sides)
• 4 Boston lettuce leaves