Parmesan Bacon Potato Gratin

Ingredients

• 1 tablespoon olive oil
• 1 pound Parmesan cheese
• 4 slices bacon, crisp-cooked and crumbled
• 2 green onions, thinly sliced
• 2 tablespoons snipped fresh chives
• 1 tablespoon snipped fresh thyme
• 1 tablespoon snipped fresh rosemary
• ¼ cup unsalted butter, cut up
• 4 pounds potatoes, peeled and finely sliced (about 12 cups)
• Salt
• Freshly ground black pepper
• ¾ cup whole milk
• ¾ cup whipping cream
• 3 tablespoons all-purpose flour
• Snipped fresh rosemary and thyme