Whisk together the olive oil, lemon juice, honey, garlic, dijon mustard, oregano, salt, and black pepper. Place the skirt steak in a shallow dish and pour over half the marinade, turning the pieces to coat. Cover and marinate for 30-45 minutes at room temperature or up to 2 hours in the fridge. Allow the steak to reach room temperature before cooking.

While the steak marinates, cook the couscous according to the package instructions. Drain the couscous into a colander, rinse under cold water to cool, let drain, and pat dry. Toss with the remaining marinade, cucumber, scallions, dill, parsley, mint, and feta (if using). Season with salt and pepper to taste.

Preheat the grill to medium-high heat (about 450?-500? F) or heat a cast iron pan on high. Cook the steak for 3-4 minutes per side or until cooked to your liking. Let rest for 10 minutes before slicing against the grain. Sprinkle with flaky sea salt and serve with a squeeze of fresh lemon juice.