On clean work surface, crush half the peppercorns with back of spoon.
Melt butter in saucepan over medium heat. Add onion and all the peppercorns; saute 4 to 5 minutes or until browned. Carefully add brandy; scrape up any browned bits from bottom of pan with wooden spoon; cook 30 seconds. Stir in flour; cook, stirring, 2 minutes.
Add beef broth; bring to boiling, stirring. Reduce heat; simmer 2 to 3 minutes. Add heavy cream; cook, stirring, 1 to 2 minutes. Remove from heat; cover sauce to keep warm.
Heat large nonstick skillet over medium heat. Season beef patties with salt and pepper. Add patties to skillet; cook 1 to 2 minutes on each side or until an instant-read thermometer inserted in centers registers 160°F.
To serve, place each patty on a plate with sauce, or serve in a bun with seasoned fries if desired.