Greek lamb burgers with spinach and red onion salad Recipe

• 1/3 cup chopped fresh mint
• 2 teaspoons paprika
• ¾ teaspoon ground cinnamon
• ½ teaspoon salt
• 3 tablespoons olive oil
• 1 1/3 lbs ground lamb
• 4 hamburger buns
• 1½ cups baby spinach leaves
• 1 1/3 cups crumbled feta cheese
• 4 (1/4-inch) red onion slices
• 1½ teaspoons balsamic vinegar

Directions