Heat grill to high heat.
In a bowl, add the ground beef, salt, garlic and herb seasoning, and Worcestershire sauce. With your fingers, toss lightly to combine (you don't want to overmix meat ever or it'll end up tough).
Put cracked pepper onto a plate.
Divide the beef into 8 portions. Place a piece of Boursin on 4 of the beef portions. Top each with of those 4 with another beef portion, and form each into a hamburger patty. Dredge each patty in cracked pepper.
Spread the butter on each side of burger bun. Grill the burgers 3-4 minutes per side until desired doneness. Grill the buns, cut and buttered sides down, a minute or two until toasty.
To serve, place a bottom half of bun on a plate. Top with a burger, slice of tomato, and the top half of bun. Serves 4.