Add the soft butter to a bowl (if it’s too hard, 20 seconds in the microwave should soften it just enough). Stir through the grated shallot and herbs and season well with salt and pepper.
If you are making the butter ahead to use later then place it onto a sheet of clingfilm. Roll into a sausage shape then chill in the fridge.
When you are ready to cook the corn take a little of this butter, a scant teaspoon, and rub all over a head of corn using clean hands. Repeat with the remaining corn. Reserve the rest of the butter for after cooking.
Lay the buttered corn on the grill bars of the barbecue and cook for about 15 minutes, turning frequently, until they are lightly charred in places and the corn is tender. Serve immediately with the rest of the butter dotted on top.