Char-broiled Beef Tenderloin Sandwich* Recipe

Make compound butter

In a small bowl, combine softened unsalted butter, minced shallot, chopped parsley, chives, lemon juice, Worcestershire sauce, salt, and black pepper. Mix thoroughly until evenly combined. Spoon onto plastic wrap, form into a log about 1-inch diameter, wrap tightly and refrigerate until firm (at least 30 minutes).

Prepare onions

Separate thinly sliced onion rings and place in a bowl. In a second bowl, whisk together flour, cornstarch, smoked paprika and salt.

Coat and fry onions

Heat vegetable oil in a heavy skillet or Dutch oven to 350°F (175°C) or medium-high until shimmering. Toss onion slices in the flour mixture until well coated, shaking off excess. Fry in batches for 2–3 minutes per batch, stirring gently, until golden brown and crisp. Remove with a slotted spoon to a paper towel-lined tray and season immediately with a pinch of salt. Keep warm or crisp in a low oven (200°F/95°C).

Cut and soak potatoes

Cut peeled russet potatoes into 1/3-inch sticks. Place in a bowl of cold water and soak 30 minutes to remove excess starch; drain and pat very dry with towels.

Fry potatoes (first fry)

Heat vegetable oil in a heavy pot to 325°F (160°C). Fry potatoes in batches for 3–4 minutes until soft but not colored. Remove and drain on paper towels.

Fry potatoes (second fry)

Increase oil temperature to 375°F (190°C). Fry potatoes again in batches for 1.5–3 minutes until golden and crisp. Drain on paper towels, immediately season with fine sea salt and black pepper, and keep warm.

Prepare the beef

Trim any silver skin from the beef tenderloin and pat dry. Tie into an even log if needed for uniform cooking. Rub with 1 tbs olive oil, then season all over with 1 tsp kosher salt and 1/2 tsp freshly ground black pepper. Let rest at room temperature 20–30 minutes while other components finish.

Char-broil or high-heat sear

Preheat a grill to high (or set a cast-iron skillet or grill pan over high heat). When very hot, place the tenderloin on the grill and sear for 2–3 minutes per side to develop a deep crust, rotating to get even char all around, then reduce heat or move to indirect heat to finish. Cook to an internal temperature of 125°F (52°C) for medium-rare (approximately 8–12 minutes total depending on thickness). Use an instant-read thermometer for accuracy. Remove and tent loosely with foil; rest 8–10 minutes.

Toast buns and assemble

While beef rests, slice buns and spread 1/2 tbs unsalted butter on cut sides. Toast on the grill or in a skillet until golden. Slice the rested tenderloin into 8–10 thin slices across the grain. Spread 1 tbs Maitre d'Butter on the bottom of each toasted bun. Layer a small handful (about 1/2 cup) of mixed greens, then 2–3 slices of tenderloin, then a generous pinch of crispy onions. Top with the bun crown. Serve immediately with hot French fries on the side.