Heat grill to high. In a medium bowl, use a fork to gently combine beef, mustard, and Worcestershire sauce; season with salt and pepper. Gently form mixture into four 1-inch-thick patties.
Place patties on hottest part of grill; sear until browned, 1 to 2 minutes per side. Move patties to cooler part of grill; continue grilling until desired doneness, 4 to 8 minutes per side.
Split the hamburger buns and toast on the grill if you like; place a burger on each bun and serve with the desired accompaniments.
Suggested accompaniments: cheese slices, sliced beefsteak tomatoes, red and white onions (raw or grilled), ketchup, mustard, pickles, mayonnaise, Boston lettuce leaves