Dad's Famous Potatoes | Recipe Reader

Ingredients

• ***For the potatoes:***
• butter or oil, to taste, for greasing the baking dish
• 3 pounds (6-7 medium) Yukon Gold potatoes, thinly sliced into 1/8-inch rounds
• 1/2 white or yellow onion, cut into slices
• ***For the sauce:***
• 2 tablespoons salted butter
• 1/4 cup all-purpose flour
• 1 1/2 cups milk, may substitute unsweetened almond milk or skim
• 1 (8-ounce) package sharp cheddar cheese, shredded
• 1/2 teaspoon garlic powder
• 3/4 teaspoon salt, plus more, to taste
• freshly ground black pepper, to taste
• ***For the topping:***
• 1/2 cup Gruyère cheese
• 1/4 cup parmesan, grated
• fresh parsley, optional, to taste, chopped, for garnish