Grill or oven - Spread out one sheet Aluminum foil for each ear of corn. Put the ear on it, and put 3 ice cubes along the ear of corn. Sprinkle with salt to taste. Put one or 2 pats of butter on top. Roll up the foil on top and seal the ends. In the oven, 375 for about 45 min should do it. On the grill, I put them around the outside fo my Weber covered grill. Coals in the middle. Turn them every 15 min for 45 min. Works this way for me. Turn the corn, wait 15 min, turn the corn, wait 15 min, turn the corn put the steaks on. All done same time.
The ice cubes melt and steam the corn and the butter ans salt run all through it.
Check me on the oven. It has been a while. look at one after about 30 min.