Bill Knapp'S Au Gratin Potatoes Recipe

Ingredients

• 3 cups of peeled and thinly sliced russet potatoes
• 3 tablespoons of unsalted butter
• 3 tablespoons of all-purpose flour
• 2 cups of whole milk (warm)
• 1 teaspoon of salt
• 1/4 teaspoon of ground black pepper
• 1/4 teaspoon of onion powder
• 1/4 teaspoon of garlic powder
• 1 1/2 cups of shredded sharp cheddar cheese (divided)
• 1/4 cup of grated Parmesan cheese
• Optional: 2 tablespoons of chopped fresh parsley for garnish