Shrimp Burger

Ingredients

• Burgers:
• 2 slices high-quality whole-wheat bread
• 2 pounds raw large shrimp, peeled, deveined, and divided
• 1 egg white
• 1 tablespoon grated onion
• 3/4 tablespoon Old Bay seasoning
• 1/4 teaspoon freshly ground black pepper
• 1/4 cup chopped parsley
• Sauce:
• 1/4 cup light mayonnaise
• 1/4 cup light sour cream
• 1 1/2 teaspoons lemon zest
• 1 tablespoon lemon juice
• 2 teaspoons capers, chopped (optional)
• 1 teaspoon prepared horseradish
• 1 teaspoon chopped parsley
• Remaining Ingredients:
• 3 teaspoons canola oil, divided
• 6 hamburger buns, toasted
• 6 romaine lettuce leaves
• 6 (1/4-inch-thick) slices tomato