Preheat the oven to 425 degrees. Place radicchio on a rimmed baking sheet. Season with salt and pepper.
Roast radicchio for 5 to 8 minutes, until tender but still crisp.
Add vinegar to a medium saucepan. Cook on medium-high heat for 5 minutes, until vinegar is reduced by half and is thickened. Stir in garlic powder and Dijon mustard.
Stir together parsley and basil in a small bowl.
Add radicchio to a serving platter. Drizzle with balsamic mixture and sprinkle with fresh basil and parsley mixture. Serve immediately.