1 tablespoon vegetable oil plus more for grill
1/2 cup (1 stick) unsalted butter, room temperature
1 tsp coarsely ground black pepper plus more
1/2 tsp kosher salt plus more
1 1/2 pounds hanger, flank, or skirt steak
1 bunch radishes with greens, halved
Flaky sea salt
Lemon wedges (for serving)
Prepare grill for medium-high heat; lightly oil grill grate. Mix butter, 1 teaspoon pepper, and 1/2 teaspoons kosher salt in a small bowl; set aside.
Season steak with kosher salt and pepper. Grill, turning occasionally, 7–10 minutes for medium-rare. Let rest 5 minutes, then top with pepper butter.
Meanwhile, combine radishes and remaining 1 tablespoon oil in a medium bowl; season with kosher salt and pepper and toss to coat. Grill radishes until crisp-tender, about 2 minutes per side.
Season steak with sea salt, slice, and serve with radishes and lemon wedges.
Serve with a sprinkling of fresh thyme (Or chives work well too!)