How to Make It
In a medium bowl, combine the butter, green garlic, chives, thyme, crushed red pepper, lemon juice and pastis. Stir well. Spoon the butter onto a sheet of plastic wrap, roll it into a log and twist the ends to seal. Refrigerate until firm, about 30 minutes.
Light a grill. Top each shucked oyster with a 1/4-inch-thick slice of the butter. Grill the oysters over high heat just until the liquor is bubbling around the edges and the butter is melted, about 3 minutes. Serve hot.