1/2 cup unsalted butter (4 ounces), softened
2 1/2 tablespoons white miso
1 cup pineapple juice
1/2 cup water
1/2 cup drained kimchi (such as Wildbrine Korean Kimchi)
1/4 cup packed light brown sugar
1/4 cup ketchup
1 (1 1/2-pound) hanger steak (about 1 1/2 inches thick)
2 teaspoons kosher salt
White sesame seeds and thinly diagonally sliced scallions, for garnish
2 pounds mixed grilled vegetables (such as squash, zucchini, baby bell peppers, and/or scallions)

Step 1
Stir together butter and miso in a small bowl until well blended. Chill miso butter in an airtight container until ready to serve, up to 5 days.

Step 2
Process pineapple juice, 1/2 cup water, kimchi, brown sugar, and ketchup in a blender until very smooth, about 25 seconds. Transfer to a large saucepan. Bring to a simmer over medium. Simmer, stirring occasionally, until thickened and reduced to about 1 cup, about 15 minutes (glaze will be grainy). Set kimchi glaze aside at room temperature.

Step 3
Season steak all over with salt. Let stand at room temperature 30 minutes. Meanwhile, preheat grill to high (450°F to 500°F). Brush one side of steak with kimchi glaze; place steak, glazed side down, on oiled grates, and brush top with some of the kimchi glaze. Grill, uncovered, until glaze is caramelized in spots, about 12 minutes for medium-rare, turning and basting often with kimchi glaze. Transfer steak to a cutting board, and let rest 10 minutes. Cut steak against the grain into slices, and divide among 4 plates. Garnish steak with sesame seeds and scallions, and serve with your favorite grilled vegetables tossed in miso butter to taste.