Shrimp Burger with Creole Mayo Recipe

Name: Shrimp Burger with Creole Mayo Recipe
Prep time: 15 min
Cook time: 18 min
Total time: 33 min
Cuisine: American
Ingredients: 1 Tbsp. butter; 1 red bell pepper, seeded, minced; ½ medium onion, minced; ¾ tsp. salt, divided; 1 lb. raw shrimp, peeled, deveined, tails removed; ½ cup plain breadcrumbs; 2 Tbsp. Creole seasoning, divided; ½ cup + 1 Tbsp. mayonnaise, divided; 2 Tbsp. cooking oil (olive oil, vegetable oil, or grapeseed oil); 8 Romaine lettuce leaves, ribs removed; 4 burger buns, split