Preheat your oven to 400°F (200°C). Place the unpeeled garlic cloves on a piece of aluminum foil, drizzle with a little olive oil, and wrap tightly. Roast in the oven for about 20-25 minutes or until soft.

Once the garlic is cool enough to handle, squeeze the cloves out of their skins into a bowl. Add the softened butter, chopped chives, and balsamic vinegar. Mix until well combined. Season with salt and pepper to taste. Set aside.

In a skillet over medium heat, add the sliced shallots and a drizzle of olive oil. Cook, stirring occasionally, until they are caramelized and charred, about 10-15 minutes. Remove from heat and set aside.

Season the filet mignon steaks generously with salt and black pepper. Heat a cast-iron skillet over high heat. Add the black truffle oil.

Once the oil is hot, sear the steaks for 3-4 minutes on each side for medium-rare, or until they reach your desired level of doneness. During the last minute of cooking, add the charred shallots back to the skillet to warm them through.

Place the seared filet mignon on a plate, top with the charred shallots, and add a generous dollop of the roasted garlic and chive confit butter on top. Garnish with fresh rosemary and serve immediately.