• Adjust rack to top position (top and bottom positions for 4 servings) and preheat oven to 425 degrees. Wash and dry produce. • Dice potatoes into 1/2-inch pieces. Trim, peel, and cut carrots on a diagonal into 1/2-inch-thick pieces. Strip half the thyme leaves from stems (all for 4); roughly chop leaves. Peel and mince or grate garlic. Trim and thinly slice scallions, separating whites from greens.

• Toss potatoes on one side of a baking sheet with a drizzle of olive oil; season generously with salt and pepper. • Toss carrots on empty side with a drizzle of olive oil; season with salt and pepper. (For 4 servings, divide between 2 sheets; roast potatoes on top rack and carrots on bottom rack.) • Roast on top rack until golden brown and crispy, 20-25 minutes.

• Meanwhile, pat steak* dry with paper towels; season generously all over with salt and pepper. • Heat a drizzle of oil in a large pan over medium-high heat. Add steak and cook to desired doneness, 4-7 minutes per side. • Turn off heat; transfer to a cutting board to rest. Wipe out pan.

• Heat a drizzle of olive oil and 1 TBSP butter (2 TBSP for 4 servings) in same pan over medium-high heat. Add chopped thyme, garlic, and scallion whites; cook until fragrant, 30 seconds.

• Stir stock concentrate and 1/4 cup water (1⁄3 cup for 4 servings) into pan with aromatics. Bring to a simmer, then stir in any resting juices from steak; cook until slightly thickened, 1-2 minutes. • Remove pan from heat. Stir in sour cream until smooth. Season with salt and pepper.

• Slice steak against the grain. • Divide steak, potatoes, and carrots between plates. Spoon sauce over steak. Garnish with scallion greens and serve.