Preheat oven to 400 degrees F. Line a baking sheet with parchment paper and set aside. Cut each radicchio in half from top to bottom. Cut each half into 3 wedges and lay on prepared baking sheet. Drizzle with olive oil and a large pinch of salt and pepper, and gently toss to coat in oil. Roast for 25 minutes or until browning. Remove from oven and set aside.