Wagyu Skirt Steak Roulade Recipe | Food Network

Ingredients

• 4 large red onions, sliced into 1/4-inch rings
• 1 cup balsamic vinegar
• One 8-ounce wagyu skirt steak, cleaned and trimmed
• Salt and freshly ground black pepper
• 1 tablespoon Dijon mustard
• 2 tablespoons flat-leaf parsley leave, finely chopped
• 1 teaspoon fresh rosemary needles, chopped
• 1 cup grated Parmesan
• Olive oil, for brushing
• Fire-roasted piquillo peppers, for serving