Sirloin and Sherry-Shallot Sauce

Lightly oil a baking sheet. In a large bowl, combine potatoes, 2 TBSP olive oil, garlic powder, and a couple large pinches of salt and pepper; toss until potatoes are completely coated. Arrange potatoes on prepared sheet into clusters (about 6 slightly overlapping slices each). Roast on middle rack for 10 minutes.

Meanwhile, toss green beans on a second baking sheet with a drizzle of olive oil, salt, and pepper. Once potatoes have roasted 10 minutes, remove from oven and sprinkle with Parmesan. Return to middle rack and place green beans on top rack. Roast until potatoes are tender, cheese is lightly browned, and green beans are tender, 12-15 minutes.

While green beans roast, pat steak dry with paper towels; season all over with salt and pepper. Heat a large drizzle of oil in a large pan over medium-high heat. Add steak and cook to desired doneness, 4-6 minutes per side. Turn off heat; transfer to a cutting board to rest. Wipe out pan.

Heat a drizzle of oil in same pan over medium heat. Add shallot and cook, stirring, until softened, 1-2 minutes. Pour in 2½ tsp vinegar (save the rest for another use). Simmer until reduced by half, 15-30 seconds. Stir in ¼ cup water and stock concentrate. Simmer until thickened, 2-3 minutes. Turn off heat. Stir in sour cream and 1 TBSP butter. Season with salt and pepper.