German Hamburger Patties

Ingredients

• 1 medium yellow onion, finely chopped
• 3 slices stale bread
• 1/4 cup milk
• 1 clove garlic, minced
• 1/2 pound ground beef (80% lean recommended)
• 1/2 pound ground pork
• 1 egg
• 1/4 cup fresh parsley, chopped
• 1 1/2 teaspoons salt
• 3/4 teaspoon black pepper
• 1 teaspoon prepared dijon mustard
• 1 teaspoon dried oregano
• 1 teaspoon paprika
• 1/2 teaspoon ground ginger
• 1/4 teaspoon ground mace
• 1/4 teaspoon ground coriander
• 4 tablespoons olive oil, divided
• 1 tablespoon butter