Cut potatoes into 1/4" sticks and pat dry.

Place on prepared baking sheet and toss with 1 tsp. olive oil, 1/4 tsp. salt, and a pinch of pepper. Spread into a single layer.

Roast in hot oven until lightly browned, 25-28 minutes, carefully tossing once halfway through.

While frites roast, continue recipe.

Halve and peel onion. Slice halves into thin strips.

Combine ground beef and a pinch of salt in a mixing bowl. Form mixture into two equally-sized patties, about 5" in diameter.

Place a medium non-stick pan over medium-high heat and add 1 tsp. olive oil. Add onions to hot pan. Stir occasionally until tender and caramelized, 10-13 minutes.

If pan becomes dry, add water, 1 Tbsp. at a time, as needed.

Add balsamic vinegar and stir occasionally until vinegar has evaporated, 2-3 minutes.

Remove from burner.

While onions cook, continue recipe.

Place a large non-stick pan over medium heat. Add rolls, cut-side down, to hot, dry pan. Toast until lightly browned, 2-3 minutes.

Transfer rolls to a plate. Keep pan over medium heat; no need to wipe clean.

Add patties to hot, dry pan. Cook until lightly charred and beef reaches a minimum internal temperature of 160 degrees, 4-6 minutes per side.

Remove from burner.

Tear cheese slices into smaller pieces.

In a microwave-safe bowl, combine cheese pieces, softened cream cheese, and 2 Tbsp. water. Cover with a damp paper towel. Microwave covered until melted and bubbling, 60-90 seconds.

Carefully remove from microwave and stir in truffle salt until combined and smooth.

Plate dish as pictured on front of card, topping bottom roll with patty, fondue, onions, arugula, and top roll. Serve aioli on the side for dipping frites. Bon appétit!