Divide the shrimp in half. Put half the shrimp into a food processor and grind it up. Transfer the shrimp to a bowl using a rubber spatula. Add the whole shrimp to the bowl. Add celery, onion, bell pepper, garlic and parsley to the processor and pulse-grind it into a fine chop. Add the vegetable mixture to the shrimp. Add half a palm full of crab boil seasoning, 1/2 teaspoon cayenne, lemon zest, salt and pepper to the bowl, to season. Stir the shrimp mixture to combine.
Preheat a large nonstick skillet over medium to medium high heat. Add extra-virgin olive oil, 2 turns of the pan in a slow stream. Use a large metal scoop to scoop 4 mounds of shrimp burger mixture into the pan. Gently pat down to form patties. Fry patties 3 to 5 minutes on each side, until they firm up and the shrimp turn whitish-pink.
Split and toast the sandwich size English muffins. Mix mayonnaise and chili sauce, salsa or taco sauce. Place burgers on muffin bottoms and top with lettuce. Slather the top of the muffins with sauce and set in place.