Faux Filet Grillé, Sauce Moutarde Recipe

Bring steak to room temperature

Remove the 200 g sirloin from the refrigerator 30–45 minutes before cooking so it comes to room temperature. Pat dry thoroughly with paper towel.

Season

Rub the steak on both sides with 1 tbs vegetable oil, then season evenly with 1 tsp kosher salt and 1/2 tsp freshly ground black pepper.

Preheat pan or grill

Heat a heavy skillet (cast-iron preferred) or a grill over high heat until very hot (pan should be smoking lightly). If using a skillet add 1 tbs oil to coat.

Sear and cook

Place the steak in the hot pan or on the grill. Sear without moving for 2–3 minutes to develop a brown crust. Flip and add 10 g unsalted butter to the pan; cook the second side 2–3 minutes for medium-rare (internal temp about 54–57°C / 130–135°F). Adjust time ±1–2 minutes for thinner/thicker steak or desired doneness.

Rest

Transfer the steak to a plate, tent loosely with foil and let rest for 5–8 minutes so juices redistribute.

Sweat shallot

While the steak rests, use the same pan (wipe out any burnt bits if necessary but keep fond). Melt 15 g unsalted butter over medium heat. Add the finely minced shallot and cook 1–2 minutes until softened and translucent, not browned.

Deglaze

Pour in 60 ml dry white wine or chicken stock and scrape the bottom of the pan to release browned bits. Simmer until reduced by about half, roughly 1–2 minutes.

Add mustards and cream

Reduce heat to low, then whisk in 2 tbs Dijon mustard and 1 tsp whole grain mustard. Add 120 ml heavy cream and stir to combine. Bring to a gentle simmer—do not boil—until sauce thickens slightly, about 2–3 minutes.

Finish seasoning

Remove from heat and swirl in 1 tsp fresh lemon juice and 1 tsp fresh thyme leaves (if using). Season with 1/2 tsp salt and 1/4 tsp freshly ground black pepper. Taste and adjust seasoning or mustard level to preference.

Mount with butter

For a glossy finish, whisk in the 15 g butter (if any remains) or an additional 5–10 g cold butter by little pieces off the heat until incorporated.

Slice the rested steak against the grain if serving sliced, or leave whole. Spoon the warm mustard sauce over the steak or serve on the side. Sprinkle 1 tsp chopped fresh parsley over the top and serve with a lemon wedge.