To the bowl of a small food processor, add destemmed herbs and pulse for about 30 seconds until evenly chopped. Add butter and a few cranks of salt and pepper, then pulse again for another 30 seconds until completely combined. Alternatively, use a knife to finely chop the destemmed herbs, then add them to a medium-sized bowl with the butter, salt and pepper. Use a spatula to fold the ingredients together until evenly combined.
Add butter to the center of a sheet of parchment paper, placing it in a mound. Lift the bottom half of the parchment paper up and over the butter so the mound is now at the bottom of the parchment. Begin at the bottom of the parchment where the butter is, and roll the parchment upward to form it into a log. Twist the ends to the butter is completely enclosed.
Refrigerate until firm.