Heat oven to 450 degrees. Cut kohlrabi into 1/4-inch-thick slices, then cut in half to form half-moon slices.
Combine oil, garlic, salt and pepper in a bowl. Add kohlrabi and toss to coat both sides. Spread kohlrabi in a single layer on a baking sheet lightly brushed with olive oil.
Bake until lightly browned, about 15 minutes.
Sprinkle cheese over the kohlrabi (top side only), return to the oven and bake about 5 minutes, or until the cheese has lightly browned.
If using parsley, sprinkle lightly over the kohlrabi before serving.