Au Gratin Potatoes

Bahan-bahan (8 porsi)

• 2 tablespoons unsalted butter, (softened)
• 4 -5 large russet potatoes, (washed)
• 1 cup heavy whipping cream
• ½ cup whole milk
• 2 tablespoons flour
• 2 teaspoons salt
• 1 teaspoon pepper
• 3 cloves garlic, (minced)
• 1 shallot, (minced)
• 1 tablespoon freshly chopped parsley
• ¾ cup shredded sharp cheddar cheese, (divided)
• ¾ cup shredded parmesan cheese, (divided)
• Fresh parsley for garnish