Preheat a grill to medium-high. In a bowl, season 3 tablespoons extra-virgin olive oil with 2 crushed garlic cloves. Halve 8 small heads baby bok choy lengthwise. Cut 3 ounces thinly sliced prosciutto into ribbons and stuff between the leaves of the bok choy. Thread 2 stuffed bok choy raft-style onto two 10-inch skewers, tucking the leaves in. Repeat to make 4 double-skewered kebabs. Brush both sides of the bok choy with the garlic oil; season with salt and pepper. Grill, flipping once, until crisp-tender, about 8 minutes.
