Gorgonzola potatoes au gratin |

Ingredients

• ¼ stick unsalted butter
• 1 medium shallot, peeled and chopped
• 3 cloves garlic, peeled and chopped
• 1 ½ pounds Yukon gold potatoes, peeled
• 1 ½ pounds yams, peeled
• 3 tablespoons all purpose flour
• 1 tablespoon kosher salt
• 1 tablespoon freshly ground pepper
• 2 tablespoons thyme leaves (removed from stems)
• 2 cups half & half
• ½ pound Gorgonzola Dolce, crumbled (freeze for up to ½ hour to harden and ease crumbling)
• Grated Parmesan Reggiano
• Fresh thyme sprigs
• Black pepper