Combine beef with garlic, onion, Worcestershire and Kosher salt. Form 4 large patties slightly thinner at center and thicker at edges for even cooking; make the edges as uniform as possible. Pour black pepper into a shallow dish and roll the edges of the burgers into the peppercorns, coating evenly, to crust the edges of each patty.
Heat a cast-iron skillet over medium-high heat. Heat a griddle for the buns or preheat the broiler to toast them on a baking sheet.
In a small bowl, combine crème fraîche with the Dijon mustard, capers, parsley.
Add oil to hot pan, 1 turn of the pan, and add butter to oil; swirl. Add burgers and cook 7-8 minutes for pink centers, turning occasionally. Remove the burgers to a plate and deglaze the pan with the brandy or cognac. Let cook a minute or so then remove from heat.
Pile cress on bun bottoms, top with patties and spoon some of the pan juices over them. Slather bun tops with crème friache sauce and set in place.
A burger fancy enough for date night? Oui!