Filet Mignon Panini Recipe

Prepare and sear filet

Pat the filet mignon dry and slice into 1/4-inch thin medallions across the grain. Toss the slices with 1 1/2 tablespoons olive oil, 1 teaspoon kosher salt, and 1/2 teaspoon freshly ground black pepper until evenly coated.

Heat a heavy skillet or cast-iron pan over medium-high heat until very hot (about 2–3 minutes). Add the steak slices in a single layer (work in two quick batches if necessary) and sear for 45–60 seconds per side for medium-rare thin slices. Transfer seared slices to a plate and tent with foil to rest while you finish other components.

Caramelize onions

In the same skillet (wipe out if burnt spots remain), warm 1 tablespoon olive oil and 1 tablespoon unsalted butter over medium heat. Add the thinly sliced onions and sprinkle 1/4 teaspoon kosher salt over them. Cook, stirring occasionally, until softened and golden, about 12–18 minutes. If onions begin to brown too quickly, reduce heat to medium-low.

When onions are soft and golden, stir in 1/2 teaspoon brown sugar and 1 teaspoon balsamic vinegar. Cook another 1–2 minutes to glaze and concentrate flavor. Remove from pan and keep warm.

Make aioli

If using a fresh jalapeño, char it over a gas flame or in a hot dry skillet until blackened, then peel, seed, and roughly chop. In a blender or small food processor, combine 1/2 cup mayonnaise, the smoked or roasted jalapeño, 1 teaspoon lime juice, 1/2 teaspoon minced garlic, 1/4 teaspoon smoked paprika, 1/4 teaspoon salt, and 1/8 teaspoon black pepper. Pulse until smooth. Taste and adjust lime, salt, or spice. Transfer to a bowl and refrigerate briefly while assembling.

Assemble panini

Preheat a panini press or heavy skillet/griddle to medium-high. Spread about 1 tablespoon smoked jalapeño aioli on the cut face of both halves of each ciabatta roll. On the bottom half, layer 2 slices Swiss cheese, a portion of the seared filet slices (about 3–4 oz per sandwich), a generous spoonful of caramelized onions, and a handful (about 1/2 cup) of fresh arugula. Top with remaining Swiss slices and the top half of the roll.

Brush the outside of each roll with softened butter. Place the sandwiches on the heated panini press and grill until the bread is crisp and cheese is melted, about 3–5 minutes. If using a skillet, set a heavy pan or cast-iron skillet on top of the sandwich and press down; flip once and press again until cheese is melted and bread golden, about 3–4 minutes per side.

Remove the panini, let rest 1 minute, then slice in half. Finish with an optional pinch of coarse sea salt and freshly cracked black pepper to taste. Serve immediately.