In a small food processor, combine all the ingredients except for the butter. Pulse the mixture until the herbs are finely chopped and well combined. Add the unsalted butter to the herb mixture in the food processor. Continue pulsing until the butter is fully incorporated, creating a smooth and creamy mixture. Place a sheet of wax paper on a clean surface and transfer the chimichurri compound butter mixture onto the wax paper. Shape the mixture into a log by rolling it up in the wax paper. Refrigerate the compound butter log for at least 1 hour or until it becomes firm and holds its shape. Once chilled and firm, your chimichurri compound butter is ready to be sliced and enjoyed!