How to Make It
In a bowl, using a fork, gently stir the ground sirloin with the horseradish, tomato paste, hot sauce, Worcestershire, celery seeds, 1 teaspoon of salt and 1 teaspoon of pepper. Using 2 lids from 1-quart takeout containers, press one fourth of the beef mixture into 4 perfect patties. Transfer to a plate. Repeat to form the remaining patties.
Light a grill or preheat a grill pan. Season the patties lightly with salt and pepper. Grill over moderate heat, turning once, until medium rare within, 8 to 10 minutes. Transfer the burgers to the buns, top with mayonnaise, lettuce, tomato and cheese and serve.