Using your hands, snap ears of corn in half crosswise. Then use a knife to split each half lengthwise into quarters. Lay the quarters on the flat side, then cut each quarter in half again lengthwise to create your corn ribs.
Place corn ribs into a bowl and toss with coconut milk and a pinch of salt.
Grill on medium heat core side down until the edges start to caramelize, about 5 minutes. Flip to the kernel side, close the lid, and cook until the corn ribs are curled and the kernels are tender, about another 5-10 minutes. Remove from grill.
Transfer corn ribs to a bowl. Top with Korean chili powder, cotija cheese, and lime juice.