Boil the shrimp just until pink in salted water; drain and let cool.
In a large bowl, mix the cooled shrimp with the mayonnaise, onion glaze, celery and bell pepper.
Add the lemon juice, followed by the onion, parsley, garlic powder, lemon pepper and crushed red pepper.
Set bowl in the refrigerator at least 20 minutes to let the flavors meld.
Brush the buns with melted butter at toast in a skillet until golden brown.
Fill the buns with shredded lettuce and top with shrimp salad.