Ingredients

• 4 tablespoons butter
• 0.25 cups minced red onion
• 2 cloves garlic , minced
• 0.33 cups all-purpose flour
• 0.5 teaspoons salt
• 0.25 teaspoons pepper
• 1 cup 2% milk
• 1 cup buttermilk
• 1 cup freshly grated Parmesan cheese , divided
• 14 small potatoes , peeled and cubed

Instructions

1. 1 Preheat the oven to 350 degrees F (175 degrees C). Lightly grease a 9x13-inch baking dish.
2. 2 Melt 1 tablespoon butter in a saucepan over medium heat. Add onion and garlic; cook and stir until onion is translucent, about 5 minutes. Stir in remaining 3 tablespoons butter until melted. Sprinkle flour, salt, and pepper over onion mixture; cook and stir until mixture bubbles and thickens, about 2 minutes. Gradually whisk in milk and buttermilk, and return mixture to a boil. Stir in 3/4 cup Parmesan cheese; cook until melted and smooth, about 2 minutes.
3. 3 Arrange potatoes over the bottom of the prepared baking dish. Pour sauce over potatoes, and stir until evenly coated.
4. 4 Bake in the preheated oven for 1 hour, stirring halfway through. Stir once more, top with remaining 1/4 cup Parmesan, and bake until cheese is melted and golden brown, about 20 more minutes.

Nutrition per serving