In a small saucepan, heat the olive oil over medium heat until a deep-fry thermometer registers 300 degrees F. Remove from heat and allow to cool for 5 minutes.
Combine the garlic, parsley, basil, thyme, and scallions in a small, heat-resistant glass bowl. Carefully pour the warm oil over the herb mixture, Add the salt and pepper. Mix well.
Spoon a thin layer of the herb mixture on the bottom of an 8 by 8-inch square glass baking dish. Arrange the goat cheese slices in a single layer on top. Spoon the remaining herb mixture evenly over the top of the goat cheese. Cover the baking dish with plastic wrap and refrigerate for at least 4 hours or overnight.
To serve: Place the radicchio leaves on a serving platter, carefully place a slice of marinated goat cheese in each leaf. Drizzle with additional herb mixture and serve.