Sheet-Pan Skirt Steak With Balsamic Vinaigrette, Broccolini, and White Beans

Finely chop 2 garlic cloves. Place in a large bowl or shallow baking dish, then whisk in vinegar, Dijon, 1/2 cup oil, 1 Tbsp. oregano, 1 tsp. salt, and 1/2 tsp. pepper. Reserve 1/4 cup vinaigrette for serving; add steak to remaining vinaigrette and turn to coat. Let marinate at least 15 minutes or up to 1 hour. Meanwhile, preheat broiler and thinly slice remaining 2 garlic cloves. Toss broccolini, remaining 2 Tbsp. oil, 1 Tbsp. oregano, 1/2 tsp. salt, and 1/4 tsp. pepper on rimmed baking sheet. Broil 5 minutes, then remove from oven. Add beans and garlic and toss to combine. Set wire rack on top of broccolini mixture. Place steak on rack; discard vinaigrette. Broil steak, turning halfway through, until cooked to desired doneness, about 3 minutes per side for medium-rare. Let steak rest 5 minutes. Meanwhile, transfer broccolini mixture to a medium bowl and toss with 1 Tbsp. reserved vinaigrette, then divide among 4 plates. Thinly slice steak against the grain and serve with broccolini mixture and remaining vinaigrette alongside.