Ingredients
1/2 cup Dijon mustard
2 tablespoons fresh lemon juice, plus wedges for serving
1 garlic clove, crushed through a press
Coarse salt and ground pepper
1 large sirloin steak (about 1 1/2 pounds and 1 inch thick), trimmed and cut into 4 equal portions
1 pound red new potatoes, halved (quartered if large)
3 tablespoons olive oil
2 pounds asparagus, trimmed
Preparation
Preheat oven to 450 degrees. In a small bowl, stir together mustard, lemon juice, and garlic; season with salt and pepper. Place cup mustard mixture in a resealable plastic bag. Add steaks, and rub to coat (reserve remaining mixture for serving). Let steaks marinate at room temperature 10 minutes, or refrigerate up to 1 day.
On a large rimmed baking sheet, toss potatoes with 1 tablespoon oil; season with salt and pepper. Roast 10 minutes, then add asparagus to sheet, and toss with another tablespoon oil. Season with salt and pepper. Roast until potatoes and asparagus are tender, about 15 minutes more.
While vegetables are roasting, heat remaining tablespoon oil in a large skillet over high. Remove steaks from marinade, allowing excess to drip off; cook 4 to 5 minutes per side for medium-rare (if pan darkens quickly, reduce heat). Let rest 5 minutes. Serve steaks with vegetables and reserved mustard sauce; garnish with lemon wedges.
