• Remove stems from mushrooms. Using a spoon, scrape out and remove dark brown gills; discard gills. Whisk together vinegar, oil, miso paste, soy sauce, garlic, brown sugar, salt, pepper and chili flakes; brush over mushrooms. Marinate for at least 1 hour or up to overnight.
• Preheat grill to medium-high heat; grease grate well. Grill mushrooms for 3 to 4 minutes per side or until grill-marked and tender. Sprinkle with chopped parsley.

Tip:

• Serve the mushrooms as a vegetarian main dish if desired.
• Serve the mushrooms as burgers in a bun, or slice and toss into a salad or with pasta.