Directions

1. Preheat the oven to 200F
2. Mix the ground beef with the salt and pepper then form into 4 half-pound patties. Leave on a plate at room temperature.
3. To make the cornichon aioli, place the cornichons into a food processor and pulse several times, until the cornichons are uniformly chopped. Place into a small mixing bowl and add the mayonnaise, lemon juice and zest, garlic powder, 1/2 teaspoon salt and cayenne.
4. Heat a skillet over medium high heat for at least 5 minutes. Add the oil, then cook the burgers on side for 4 minutes, or until dark brown. Flip and cook on the other side, about 3 minutes for medium rare. Place the burgers onto an oven-proof tray and keep warm in the oven.
5. At the same time, heat the butter in a large skillet over medium heat until foaming. Add the buns and toast until golden brown on one side. Set the toasted buns aside.
6. Using the same pan, place the grated raclette over medium heat and arm until melted.
7. To assemble the burger, spread the cornichon aioli on one side of each bun, and the French onion confit on the other side of each. Place a burger patty onto the bun, then, using a spatula, pour the melted raclette over each burger.