Beef and Gorgonzola Burgers

12 ounces lean ground chuck
2 ounces Gorgonzola cheese or other blue cheese
Vegetable oil
4 1/2-inch-thick slices country-style white bread
2 large tomato slices
4 thin slices red onion
1/2 bunch arugula

Form beef into four 3-inch-diameter patties. Form cheese into two 1 1/2-inch rounds; place cheese atop two beef patties. Top each with another beef patty, sealing at edges. Season with pepper.

Prepare barbecue (medium-high heat) or preheat broiler. Brush barbecue rack with vegetable oil.

Grill burgers until charred outside but still juicy, about 3 minutes per side.

Grill bread slices until lightly toasted, about 1 minute per side.

Place each burger on 1 bread slice. Top with tomato, onion, arugula and another bread slice and serve.