Adjust racks to top and middle positions and preheat oven to 425 degrees. Wash and dry all produce. Halve potatoes lengthwise. Strip rosemary leaves from stems; chop leaves. Halve, peel, and mince half the shallot (mince whole shallot for 4 servings). Slice garlic.

On a baking sheet, toss potatoes with a large drizzle of olive oil, a pinch of chopped rosemary, pepper, and a few big pinches of salt. Roast on top rack until tender and lightly crisped, 20-25 minutes.

On a second baking sheet, toss green beans and garlic with a drizzle of olive oil, salt, and pepper. Once potatoes have roasted for 10 minutes, place green beans on middle rack. Roast until tender, 12-15 minutes.

Meanwhile, pat steak dry with paper towels. Season generously all over with salt and pepper. Heat a large drizzle of oil in a large pan over medium-high heat. Add steak and cook until browned but not yet cooked through, 3-6 minutes per side. Turn off heat; wipe out pan. Transfer steak to sheet with green beans; roast until steak is cooked to desired doneness, 4-7 minutes. (If green beans finish first, remove from sheet and continue roasting steak.) Set steak aside to rest.

Heat a drizzle of oil in pan used for steak over medium-high heat. Stir in minced shallot and a pinch of remaining chopped rosemary. Cook, stirring, until fragrant, 30-60 seconds. Stir in 1/4 cup water (1/3 cup for 4 servings), half the vinegar (use all for 4), stock concentrate, and jam. Bring to a simmer and cook until thickened, 2-3 minutes. Turn off heat. Stir in 1 TBSP butter until melted. Season with salt and pepper.

Slice steak against the grain. Divide between plates with potatoes and green beans. Top steak with sauce.