Wash and dry all produce. Preheat oven to 425 degrees. Peel potatoes, then cut into 1/2-inch cubes. Place in a medium pot with a big pinch of salt and enough water to cover by 1 inch. Bring to a boil and cook until easily pierced by a knife, 12-15 minutes. Drain and return to pot.

Use a mallet or heavy pan to crush peppercorns in their bag until coarsely ground. Finely chop parsley. Peel, halve, and chop shallot. Toss green beans, a drizzle of oil, and a pinch of salt and pepper on a baking sheet. Roast in oven until tender, 12-15 minutes.

Heat a drizzle of oil in a large pan over medium-high heat. Pat steak dry with a paper towel and season all over 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. TIP: Loosely cover steak with aluminum foil to keep it warm.

Reduce heat under pan to medium-low and add a drizzle of oil. Add shallot and cook, tossing, until softened, 1-2 minutes. Stir in 1/4 tsp crushed peppercorns (use more or less to taste), demi-glace, and 1/2 cup water. Bring to a boil, then lower heat and simmer until reduced, 2-3 minutes. Remove from heat. Add 1 TBSP butter and half the sour cream. Stir until butter is melted. Season with salt and pepper.

Add remaining sour cream and 1/2 tsp truffle oil to pot with drained potatoes (we sent extra oil—use more or less to taste). Mash with a potato masher or fork until smooth. Season to taste with salt and pepper. TIP: Add a splash of milk to make potatoes extra creamy.

Thinly slice steak against the grain. Toss green beans with almonds. Divide mashed potatoes, green beans, and steak between plates. Drizzle sauce over steak and potatoes. Garnish with parsley.