- To make the ranch seasoning : Combine all the ingredients in a food processor or spice grinder. Pulse a couple of times until it’s a coarse powder. Transfer to a jar or airtight container.
- To make the corn on the cob : Peel back the husks of the corn without detaching them. Remove and discard all the silk. Pull the husks back over the corn and place the ears in a large bowl or pot of cold water. Soak for 15 minutes.
- Heat the grill to medium-high or heat a grill pan on the stove over medium heat. Place the corn on the grill and cook for 20 minutes, flipping once halfway through, or until the husks are slightly charred and the corn is tender.
- If you want pretty grill marks on the corn, peel back the husks, place the corn directly on the grill, and cook for a couple of minutes on each side. Otherwise, just remove the corn from the grill.
- Use a kitchen towel to pull back the husks. Tie them to form a handle. Spread butter over each ear and season generously with ranch seasoning. Sprinkle with chopped parsley (if desired) and serve immediately.
- VARIATION You can also roast the corn. Remove the husks when you remove the silk and skip the soaking. Place each ear on a sheet of aluminum foil.
- Spread butter on the corn, then sprinkle generously with the ranch seasoning. Wrap the aluminum tightly around the corn. Roast at 450°F for 15 to 20 minutes, until the corn is tender.