Barefoot Contessa recipe:

2 pounds ground chuck 1 pound ground sirloin 1/2 cup seasoned dry bread crumbs 1/4 cup steak sauce (recommended: Crosse and Blackwell) 3 extra-large eggs 1 1/2 teaspoons kosher salt
3/4 teaspoon freshly ground black pepper 8 to 10 hamburger buns 8 ounces blue cheese, sliced (recommended: Danish Blue) Arugula and sliced tomatoes, for serving, optional Onions & sugar (to carmelize for topping)
Mix the meats, bread crumbs, steak sauce, eggs, salt, and pepper with the tines of a fork, but do not mash them. Lightly form hamburger patties and press lightly into shape. Prepare a charcoal or a stove-top grill. Cook the hamburgers for 4 minutes on 1 side, then turn and cook 3 minutes on the other side for medium-rare. Remove to a plate and cover with aluminum foil. Allow the hamburgers to rest for 5 minutes. Meanwhile, grill the buns, and cook and carmelize onions. Dress the burgers with anything you desire and serve.