Ingredients
Method
Roast the Brussels Sprouts
- Preheat your oven to 425°F. Trim and halve the Brussels sprouts, toss with olive oil, salt, and cracked black pepper. Spread cut-side down on a sheet pan and roast for 12 to 15 minutes until caramelized and tender at the edges. Set aside.
Make the Sweet Potato Purée
- Peel and cube the sweet potatoes into 1-inch pieces. Boil in salted water until fork-tender, about 15 to 18 minutes. Drain and return to the pot over low heat for 1 minute to steam off excess moisture. Pass through a ricer or mash very well.
- Over low heat, stir in the cold butter one tablespoon at a time until fully incorporated. Add the warm heavy cream a little at a time until the purée is silky and smooth. Stir in the brown sugar and nutmeg. Season with salt and white pepper.
Adding butter cold and one tablespoon at a time creates a stable emulsion. If you dump in warm butter all at once the fat separates and the purée turns greasy. Low heat, patience, one piece at a time.
Sear the Filet Mignon
- Pull the filets from the refrigerator 30 to 45 minutes before cooking. Pat completely dry with paper towels. Season generously with kosher salt and cracked black pepper on all sides.
- Heat a cast iron or heavy skillet over high heat until smoking. Add the neutral oil. Sear the filets for 3 to 4 minutes per side without moving them.
- Reduce heat to medium, add the butter, garlic cloves, and thyme sprigs. Tilt the pan and baste the filets continuously for 1 to 2 minutes. For medium-rare, internal temperature should read 130°F. Remove from the pan and rest on a wire rack for 5 to 7 minutes.
Bringing the meat to room temperature is not just a chef habit. It means the center reaches temperature at the same rate as the outside, giving you an even cook from edge to edge, not a gray band around a pink center.
Resist the urge to move or check the filet. A proper crust only forms from sustained contact with the pan. If it sticks when you try to flip, it is not ready. Give it another 30 seconds.
Build the Apple-Brandy Glaze
- Discard excess fat from the pan but keep the fond. Reduce heat to medium. Add the butter and sauté the shallots for 2 to 3 minutes until softened. Add the diced apples and cook for another 2 minutes.
- Carefully add the brandy (it may flame briefly) and let it reduce by half, about 1 minute. Add the demi-glace or beef stock and thyme leaves. Simmer for 6 to 8 minutes until the sauce thickens and coats a spoon.
- Stir in the Dijon mustard. Taste and adjust salt and pepper.
If the brandy flames, do not panic. Let it burn off naturally. It goes out on its own in seconds and the alcohol cooks off completely. Stand back, do not cover the pan, and let it do its thing.
Plate and Serve
- Spoon a generous mound of sweet potato purée in the center of each plate. Set the rested filet on top. Arrange the Brussels sprouts alongside. Spoon the apple-brandy glaze over the filet and let it pool around the purée. Serve immediately.
Notes
Plating: Fan the sliced filet over a swoosh of sweet potato purée. Spoon the apple brandy glaze over the meat. Add Brussels sprouts to the side and finish with a thyme sprig.
Wine: A full-bodied Cabernet Sauvignon or a Côtes du Rhône pairs beautifully with the brandy glaze.
Prep ahead: The apple brandy glaze can be made 1-2 days ahead and reheated gently. The sweet potato purée can also be made ahead and reheated with a splash of warm cream.
Feeding more people: Scale all components proportionally. Sear the steaks in batches to avoid crowding. Finish in a 400°F oven for 4-5 minutes.
Swaps: Veal demi-glace is ideal but rich beef stock works. Calvados is traditional but regular brandy is fine. Sweet potatoes can be swapped for butternut squash purée.