BEEF BURGERS WITH CHEDDAR CHEESE AND CARAMELIZED ONION (Massachusetts, for four)
1-½ pounds 100% ground chuck (about 80% lean)
1 teaspoon salt
½ teaspoon ground black pepper
vegetable oil for grill rack
4 hamburger buns
2 tablespoons extra virgin olive oil
1 large yellow onion, sliced crosswise into ¼ inch rings
one 12 ounce bottle stout
4 slices aged white cheddar cheese
Dijon mustard to taste
1. Break up chuck to increase surface area for seasoning. Sprinkle salt and pepper over meat and toss lightly with hands to distribute. Divide meat into 4 equal portions (6 ounces each). With cupped hands, toss one portion back and forth to form a loose ball. Pat lightly to flatten meat into a ¾ inch thick burger that measures about 4-1/2 inches across. (Do not over-handle meat or your burger will be tough). Pressing down with your thumb, or with the back of a measuring spoon, make a ¼ inch depression in the center of each patty, creating a shallow well. (This makes them come out flat, not puffed in the center). Repeat with remaining portions of meat.
2. Heat olive oil in a 4 quart saucepan over high heat. Add sliced onion and cook, stirring occasionally, until browned, about 8 minutes. Add stout and cook until onions are tender and the stout has almost evaporated, about 20 minutes.
3. Heat a well-seasoned large cast-iron skillet over moderately high heat until it is hot, sprinkle it evenly with coarse salt, and when the skillet is hot enough that the salt begins to color slightly, add the patties. For medium rare burgers, cook for 4 minutes on one side, flip the burgers over and cook for 4 minutes on the other side. Add a slice of aged white cheddar cheese to each burger during the last minute of cooking and let it melt. Top with the braised onions and serve on toasted sesame seed buns lightly spread with Dijon mustard.