1 cup black peppercorns
1⁄3 cup, plus 2 tablespoons counrty-style Dijon mustard, divided
2 pounds ground chuck (80-85 percent lean)
2 tablespoons garlic cloves, minced
½ cup sweet onion, minced
¼ cup Worcestershire sauce
2 teaspoons kosher salt
1 small wheel baby Brie, sliced to fit patties
6 Kaiser rolls, split
2 cups baby spinach
Grind the peppercorns in a food processor or spice grinder to coarsely chop. Short pulses will give you a nice coarse chop. Pour into a shallow bowl and set aside.
Heat a gas grill to medium-high heat.
In a large bowl combine the ground chuck, garlic, onion, 2 tablespoons mustard, Worcestershire sauce and salt. Mix well, but handle the meat as little as possible to avoid compacting it. Divide the mixture into 6 equal portions and form patties that are slightly larger than the roll size and about ¾ inch thick. With your thumb, create a divot in the center of each burger. Brush both sides of the patties with remaining mustard, dip into the peppercorns pressing down slightly so they stick.
When the grill is ready, brush the rack with vegetable oil. Place patties on the grill with the divot side up cover and cook, turning once after 3 minutes. Allow another 2½ minutes for medium. Place the buns, split-side down, on the outer edges of the grill to toast lightly.
To assemble: Divide spinach among the bottom buns. Top with a patty, Brie slice and top bun.
Cook's note: Try these with wine-soaked pears. Core 3 large Bartlett pears (ripe, but still firm) and cut into ¼-inch thick slices. Put slices in a shallow dish with 1 bottle of Moscato and soak 15-30 minutes. Drain and grill over indirect heat, turning once, about 6-8 minutes total. Pears should have golden brown grill marks. Place on top of the spinach.