Taste: Annotated Recipe: The Rouge Burger

On summer days, the kitchen at Rouge regularly serves up more than 100 of its famous burgers. The secret behind the sensation? “Ten years of fine-tuning the recipe,” says chef Matt Zagorski. Rouge, which is celebrating a decade on Rittenhouse Square, serves its signature burger with fries — but we’ll let some secrets stay kept.

4 Tbsp. canola oil
1 white onion, sliced
Kosher salt, to taste
Black pepper, to taste
3 lb. ground beef
4 oz. gruyère cheese, cut into four thick slices
4 challah rolls
2 Tbsp. unsalted butter
4 leaves Bibb lettuce
1 beefsteak tomato, sliced
1 kosher pickle, cut into four spears

In a saucepan over low heat, heat 2 tablespoons canola oil. Add onions and season with salt and pepper. Cook slowly, stirring frequently, until onions caramelize, about 40 minutes over medium heat. Preheat oven to 400º Fahrenheit. Form ground beef into 4 12-ounce patties, each about 4 ½ inches in diameter. Season heavily with salt and pepper. In a cast iron pan over medium-high heat, heat remaining canola oil until almost smoking. Sear burgers on both sides, about 3 to 4 minutes on each. Transfer pan to oven and cook until burgers have reached desired doneness. While burgers are cooking, slice each roll in half along the equator, and butter each cut surface. Toast cut surfaces on a grill or under a broiler. Remove burgers from oven and top each with caramelized onions and gruyère. Return to oven to melt gruyère, about 1 minute. To serve, sandwich burger with roll halves. Garnish plate with lettuce, tomato and a pickle spear. Serves four.

TIPS

The Rouge kitchen follows these guidelines to cook the perfect burger: 6 minutes in the oven for a rare burger, 9 minutes for medium rare, 12 minutes for medium, 15 minutes for medium well, 17 minutes for well.

Look for hydroponically grown Bibb lettuce. Lettuce adds even more moisture to the burger.

Rouge uses buttery challah rolls from Wild Flour Bakery in the Northeast. Though the bakery is mainly wholesale, it has a stand at the Sunday morning Headhouse farmers’ market.

Go all the way; use super-rich Plugrá butter on the rolls.

The key to the Rouge burger is the meat-to-fat ratio. Look for high-quality freshly ground beef that’s 15 percent fat.

To form each patty, toss the meat back and forth between your hands until it holds a ball shape. The tighter the meat is packed, the juicier the burger will be.

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