Adjust rack to top position and preheat oven to 425 degrees. Wash and dry produce.

Cut potatoes into ½-inch dice. Mince chives.

Toss potatoes on a baking sheet with a large drizzle of oil, a big pinch of salt, and pepper. Roast on top rack until browned and tender, 20-25 minutes.

Meanwhile, in a small pot, combine cream sauce base, cream cheese, and half the mustard (all for 4 servings) over medium heat. Cook, whisking, until smooth and thickened, 2-4 minutes.

Taste and season with a pinch of salt and pepper if desired. Remove pot from heat; cover to keep warm.

Pat steak* dry with paper towels. Season all over with salt and pepper.

Heat a drizzle of oil in a large, preferably nonstick, pan over medium-high heat. Add steak and cook to desired doneness, 5-7 minutes per side.

Remove pan from heat. Add garlic herb butter; stir until melted and spoon over steak until coated.

Transfer steak to a plate to rest, pouring remaining garlic herb butter from pan over steak. Tent with foil to keep warm. Wipe out pan.

Heat a drizzle of oil in same pan over medium heat. Crack eggs* into pan and cover. (For 4 servings, you may want to cook eggs in batches.) Fry eggs to preference. Season with salt and pepper.

To sheet with roasted potatoes, add Parmesan cheese and as much truffle seasoning as you like; toss to combine.

Reheat sauce over medium-low heat, stirring occasionally.

Slice steak against the grain.

Divide steak, eggs, and potatoes between plates in separate sections. Drizzle half the sauce over steak and eggs and garnish everything with chives; serve with remaining sauce in small bowls alongside for dipping.