May 27th, 2016
From Weber's New American Barbecue: A Modern Spin on the Classics by Jamie Purviance.
In a saucepan over medium heat on the stove, saute the garlic in 1 tablespoon oil until fragrant, about 1 minute. Add the ketchup, 1/2 cup of the beer, the vinegar, brown sugar, 2 teaspoons of the Worcestershire sauce, and 1/2 teaspoon salt and bring to a gentle boil. Reduce the heat to low and simmer until the sauce is the consistency of ketchup, 15 to 20 minutes, stirring often. Let cool.
Prepare the grill for direct cooking over medium-high heat (400° to 500°F).
Brush the onion with oil, and then grill over direct medium-high heat, with the lid closed, until lightly charred, about 6 minutes, turning once. In a large disposable foil pan mix 1/2 cup of the beer, the mustard, and 1 teaspoon salt. Add the onions to the beer mixture. Grill over direct medium-high heat, with the lid closed, until most of the liquid is evaporated and the onion is soft, 10 to 15 minutes, stirring occasionally. Remove from the grill.
Mix the ground chuck, paprika, pepper, 1 1/2 teaspoons salt, the remaining 2 tablespoons beer and 1 teaspoon Worcestershire sauce, and then gently form four patties of equal size, each about 3/4 inch thick. With your thumb or the back of a spoon, make a shallow indentation about 1 inch wide in the center of the patties to prevent them from forming a dome as they cook.
Grill the patties over direct medium-high heat, with the lid closed, until cooked to medium doneness (160°F), 8 to 10 minutes, turning once. During the last 30 seconds to 1 minute of grilling time, toast the rolls, cut side down, over direct heat.
Build each burger on a roll with lettuce, a patty, onions, and sauce. Serve warm.