Preheat oven to 400. Halve potatoes lengthwise, and if large, cut into quarters lengthwise. Place on a rimmed baking sheet and toss with the garlic, rosemary, olive oil and salt. Once mixed thoroughly, toss with the cheese.
Bake for 15 minutes, then stir. Bake another 10 minutes, stirring again. Bake for a final 10-15 minutes until the cheese starts to get crispy and brown and the potatoes are cooked through. Serve warm.