Beef and Lamb Burgers with Feta Mint Spread

Ingredients

• 1/2 cup onion, finely chopped
• 1/4 cup fresh flat-leaf parsley, chopped
• 1 tsp. garlic, minced
• 1 tsp. lemon rind, grated
• 1/2 tsp. salt
• 1/2 tsp. black pepper
• 1/8 tsp. cumin, ground
• 1/2 lb. ground lamb
• 1/2 lb. 95% lean ground beef
• buttery cooking spray