1. Rub shucked ears of corn with vegetable oil, kosher salt and freshly ground black pepper, then put on preheated grill, turning several times until kernels are slightly charred; remove and allow to cool.
2. Using a sharp knife, slice down each ear of corn removing kernels in wide strips.
3. Put bread on grill until golden brown, then rub with garlic clove, discarding clove when done.
4. In a small bowl, mix together the sour cream with feta.
5. Assemble by laying out toasted ciabatta bread, spreading even layer of feta mixture on each one, then topping with grilled corn. Squeeze lime juice lightly over each and garnish with cilantro leaves and a pinch of chili powder.
Grilling the corn really brings out a sweet and smoky flavor that works so well with this sandwich. The feta cheese, cilantro, and chili powder work very well together and compliment the corn. These are fancy sandwiches that will impress the guests at your next cookout, especially if they're used to hotdogs and hamburgers coming off your grill.