Make Ahead Roasted Garlic Mashed Potatoes

Ingredients

• 1 head garlic
• extra virgin olive oil
• 4 pounds yukon gold or russet potatoes, peeled and quartered
• 2 cups heavy cream
• 2 cups whole milk
• 8 fresh sage leaves
• 3 sprigs fresh thyme
• 6 tablespoons salted butter, at room temperature
• kosher salt and black pepper