Potato Gratin: RELOADED - Alton Brown

Ingredients

• 1 tablespoon unsalted butter
• 1 cup heavy cream
• 1 cup half and half
• 5 large cloves garlic, peeled, crushed, and roughly chopped
• 10 sprigs thyme, divided
• 3 sprigs rosemary, divided
• 1 1/2 teaspoons kosher salt, divided
• 1 1/2 teaspoons freshly ground white pepper, divided
• 1/2 teaspoon freshly ground nutmeg
• 2 1/2 pounds Yukon Gold potatoes, peeled
• 3/4 cup freshly ground Parmesan cheese
• 3/4 cup freshly ground Asiago cheese