New York Strip Steak with Truffle Butter

Place potatoes in a medium pot with enough salted water to cover by 1 inch. Bring to a boil and cook until tender, about 12 minutes. Meanwhile, place milk and 1 thyme sprig in a small pot. Bring to a simmer, then remove from heat. Once potatoes are cooked, drain thoroughly and return to pot. Mash in pot with a potato masher until smooth.

Melt another 1 TBSP butter in a medium pan over medium heat. Add half the minced shallot. Cook, tossing, until just softened, 1-2 minutes. Pour shallot and melted butter into small bowl with reserved room-temperature butter. Add truffle zest and a pinch of parsley. Mash together with a fork. Set aside in freezer to chill for 10 minutes

Heat a drizzle of oil in pan used for shallot over medium-high heat. Pat steak dry with a paper towel. Season with salt and pepper. Add to pan and cook to desired doneness, 3-6 minutes per side. Remove from pan and set aside to rest. Meanwhile, toss asparagus with a drizzle of oil on a baking sheet. Season with salt and pepper. Roast in oven until just tender, about 7 minutes.

Wipe out pan after removing steak, then reduce heat under pan to low and heat another drizzle of oil in it. Add remaining shallot. Cook, tossing, until starting to soften, 1-2 minutes. Stir in demi-glace and 3 TBSP water. Let simmer until slightly thickened, about 2 minutes. Season with salt and pepper. Meanwhile, slice steak against the grain. Discard thyme sprig from pot with milk.