Preheat oven to 450 degrees. Wash and dry all produce. Bring 2 TBSP butter (4 TBSP for 4 servings) to room temperature in a small bowl. Mince or grate garlic. Trim and thinly slice scallions, separating whites from greens. Halve ciabatta (as if you were making a sandwich). Place peppercorns in a zip-close bag; crush using a rolling pin or heavy-bottomed pan.

Toss broccoli on a baking sheet with drizzle of oil, half the garlic, salt, and pepper. Roast on top rack until browned and tender, 10-15 minutes (we’ll add more to the sheet after 10 minutes).

Meanwhile, to bowl with softened butter, stir in as much remaining garlic as you like. Season with salt and pepper. TIP: If your butter is still cold, microwave until just soft but not melted, about 10 seconds.

Pat steak dry with paper towels; season 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. Spread cut sides of ciabatta with garlic butter. Once broccoli has roasted for about 10 minutes, push to one side of sheet and add garlic bread to opposite side. Roast until broccoli is tender and bread is golden, 4-5 minutes. (For 4 servings, place on a second baking sheet and roast on middle rack.)

Heat a drizzle of oil in pan used for steak over medium-high heat. Add scallion whites and 1/4 tsp crushed peppercorns (use more or less to taste). Cook until fragrant, about 2 minutes. Add stock concentrate, 1/4 cup water (1/3 cup for 4 servings), and mustard, stirring and scraping up any browned bits from bottom of pan. Simmer until reduced by half, 1-2 minutes. Remove from heat and whisk in 1 TBSP butter and sour cream.

Halve garlic bread on a diagonal. Thinly slice steak against the grain. Divide steak between plates; drizzle with gravy and sprinkle with scallion greens. Serve with broccoli and garlic bread on the side.