• Trim the root ends from the scallions; thinly slice the scallions.
• Finely chop the cilantro.
• Zest and juice the lime, keeping the zest and juice separate.
• Measure out 1 tablespoon sesame oil for the chimichurri; set aside the remaining 1 teaspoon sesame oil for finishing the plantain.

In a medium bowl, stir together the scallions, cilantro, lime zest, 1 tablespoon lime juice, 1 tablespoon sesame oil, and as much kimchi as you like; season to taste with salt and pepper. Let stand while you prepare the rest of the meal.

• Trim off the ends and peel the plantain; cut the plantain crosswise into ½-inch-thick slices.

In a medium frying pan over medium heat, warm 2 to 3 teaspoons neutral oil until hot but not smoking. Add the plantain slices, season with salt and pepper, and cook, turning once, until browned on both sides but still firm and not yet cooked through, 3 to 4 minutes. Transfer to a plate. Using the bottom of a bowl or cup, smash the plantain slices into ¼-inch-thick rounds. Do not clean the pan.

• Pat the beef dry with a paper towel; season generously with salt and pepper.

In the same pan used for the plantain, warm 1 tablespoon neutral oil over medium-high heat until hot but not smoking. Add the beef and cook, turning frequently, until well browned, 6 to 8 minutes for medium-rare for top sirloins and New York strip and 8 to 12 minutes for filet mignons. Transfer to a plate to rest for 5 minutes. Wipe out the pan.
While the beef cooks and rests, prepare the remaining ingredients.

• Remove the stem, ribs, and seeds from the bell pepper; cut the pepper lengthwise into 1-inch-wide strips, then crosswise into 1-inch-wide pieces.
• Finely chop, press, or grate enough garlic to measure 1 teaspoon.
• Grate or peel and finely chop enough ginger to measure 1 teaspoon.
• In a small bowl, stir together the honey and remaining 1 teaspoon sesame oil.

In the same pan used for the beef, warm 1 teaspoon neutral oil over medium-high heat until hot but not smoking. Add the plantain slices and bell pepper, season with salt and pepper, and cook, gently stirring once or twice, until the plantain slices are cooked through and tender when pierced with a knife and the pepper starts to soften, 2 to 3 minutes. Stir in the garlic and ginger and cook until fragrant, about 30 seconds. Stir in the honey mixture and as many chile flakes as you like and cook until evenly coated, about 30 seconds. Season to taste with salt and pepper.

Transfer the beef and plantain mixture to individual plates. Top the beef with the kimchi chimichurri and serve.