Heat oil in large saucepan over medium heat.

Add butter and allow it to brown slightly.

Add sliced onions and cook, stirring continuously, for about 10 minutes, or until onions begin to caramelize.

Add brown sugar, salt, and pepper, stir well, and continue cooking.

When onions are fully caramelized, add beef au jus and Jim Beam Black® Bourbon.

Cook until onions have a nice brown color, remove from heat, and reserve until plating.

Trim a thin slice off top and bottom of ciabatta buns to create flat surface area; then slice each bun in half horizontally.

Lightly and equally spread mayonnaise on outside of buns to enhance browning.

Pre-heat grill or large saucepan to medium heat and place buns mayonnaise-side down. Top each bun half with brie cheese slice and leave long enough to lightly toast bun and melt cheese, about 1 minute.

Grill or pan-fry burgers until internal temperature reaches 165 degrees Fahrenheit, as per a meat thermometer.

Top each burger equally with Beam Black® Bourbon onions, then place burgers on one side of toasted buns and top with remaining bun.

Cut in half and serve with hot beef au jus for dipping.

*Chef’s Note: For simple au jus, mix 1 bouillon cube with 2 cups boiling water.