Place cayenne pepper, ground cumin, balsamic vinegar, Worcestershire sauce, liquid amino/soy sauce, brown sugar, scallions, garlic, lime juice, oil in a blender then puree.
Put skirt steak and pour in marinade in a zip lock, refrigerate for at least 3 hour
Place the grill pan on the stove and turn heat to medium-high.
Brush the grill pan with olive oil using a pastry brush or spray oil
Cook the skirt steak for 4 each side for medium-rare
Transfer to a plate then cover loosely with aluminum foil for about 5 minutes
Serve with mixed salad (watercress, corn, tomatoes, micro greens, drizzle with olive oil and toss to coat; season with salt and pepper)