Pull most of outer husks of corn down to expose kernels, then remove silk. Pull husks back up to cover kernels, transfer to large bowl or roasting pan, cover with cold water and soak 30 mins.
Meanwhile, in food processor, puree butter, parsley, Parmesan, garlic, lemon zest and juice, ½ tsp salt and ¼ tsp pepper until smooth. Set aside.
Heat grill to medium-high. Pat corn very dry and grill, turning occasionally, until charred on all sides and corn is tender, 8 to 10 mins. Transfer to cutting board and let sit until cool enough to handle, then pull down husks, exposing kernels.
Return to grill and cook until slightly charred, about 5 mins. Transfer back to cutting board.
Serve with butter as well as sprinkling of Parmesan and cracked pepper if desired.
Notes
Photographed By MIKE GARTEN | Prop Styling By ALEX MATA | Food Styling By SIMON ANDREWS