French Style Filet Mignon Cubes Recipe

Prepare and cut

Trim any excess fat or silver skin from the filet mignon. Pat the beef dry with paper towels. Cut the filet into uniform 1 to 1 1/4-inch cubes so they will sear evenly (about 16–20 cubes from 1 lb).

Season

Place the cubes in a single layer on a tray and season evenly with the kosher salt and freshly ground black pepper. Let rest at room temperature for 10–15 minutes while you heat the pan (this helps the meat sear).

Sear the cubes

Heat a heavy skillet (preferably cast iron) over high heat until smoking just begins. Add 1 tablespoon olive oil and swirl to coat. Working in a single layer — do not crowd the pan — add half the cubes and sear undisturbed for 1 1/2 to 2 minutes until a deep brown crust forms. Flip and sear the opposite side 1 to 1 1/2 minutes for medium-rare (internal ~125–130°F / 52–54°C). Remove seared cubes to a warm plate and repeat with remaining cubes, adding a touch more oil if needed.

Finish with butter and aromatics

Reduce heat to medium. Return all cubes to the pan, add 2 tablespoons unsalted butter, smashed garlic cloves and thyme sprigs. As the butter melts, tilt the pan slightly and spoon the melted butter and aromatics over the cubes (baste) for 30–45 seconds to build flavor and finish cooking. Remove cubes to a warm serving plate and tent loosely with foil to rest 3–4 minutes.

Prepare shallot and deglaze

While the steak rests, carefully wipe out excess fat from the skillet, leaving browned fond. Add the halved and finely minced shallot to the skillet and cook over medium heat for 45–60 seconds until softened but not browned.

Deglaze and make pan sauce

Pour in 1 tablespoon dry red wine to deglaze the pan, scraping up browned bits with a wooden spoon. Allow the wine to reduce by half (~30 seconds). Add 1/4 cup beef demi-glace (or concentrated reduced beef stock) and stir to combine. Simmer gently 1–2 minutes to thicken slightly.

Finish sauce

Turn off the heat and whisk in 1 teaspoon whole grain mustard and 1 tablespoon (if desired) of the reserved butter from resting (alternatively an extra tsp butter) to add sheen. Taste and adjust seasoning with a pinch of salt and pepper if needed. Stir in chopped fresh parsley.

Plate and serve

Arrange the rested filet mignon cubes on a warm serving plate. Spoon the pan sauce over or alongside the cubes. Garnish with an additional thyme sprig if desired and serve immediately.