Parmesan-Crusted Au Gratin Potatoes and Onion

This recipe for potatoes and onions mixed with a creamy cheese sauce and baked with a crispy cheese topping is a terrific side dish.

• Preparation Time: 25 mins
• Cooking Time: 50 mins
• Total Time: 1 hr 15 mins
• Calories: 507 Calories

Ingredients

• 6 tablespoons butter
• 1 cup heavy whipping cream
• 6 tablespoons all-purpose flour
• 2 tablespoons chopped fresh parsley
• salt and ground black pepper to taste
• 4 pounds russet potatoes, cut into 1/4-inch slices
• 1 cup shredded Asiago cheese
• 1 sweet onion, sliced into rings
• 7 buttery round crackers (such as Ritz®), crushed
• 1.5 cups whole milk
• 2.5 cups shredded mild Cheddar cheese
• 0.75 cup sliced green onions
• 0.33333334326744 cup shaved Parmesan cheese

Recipe Instructions

Step 1

Place potatoes into a large pot and cover with water; add salt and bring to a boil. Reduce heat to medium-low and simmer until just beginning to soften, 15 to 20 minutes; drain.

Step 2

Melt butter in a saucepan over medium heat; add flour and whisk until the mixture thickens, 1 to 2 minutes. Pour milk and heavy cream into the saucepan; cook and stir until smooth, 2 to 3 minutes. Melt Cheddar and Asiago cheese into the butter mixture; cook while stirring continually until the mixture is smooth and creamy, 1 to 2 minutes. Season the sauce with salt and pepper.

Step 3

Preheat oven to 400 degrees F (200 degrees C). Butter a 9x13-inch casserole dish.

Step 4

Layer about half the sliced potatoes into the bottom of the baking dish. Top the potatoes with sweet onion slices and green onions; pour about 1/3 of the cheese sauce over the onions. Arrange the remaining potato slices into the dish; pour remaining cheese sauce over the potatoes. Sprinkle Parmesan cheese and crushed crackers over the top.

Step 5

Bake in the preheated oven until hot in the center and beginning to brown at the edge, about 30 minutes. Sprinkle parsley over the top of the dish to serve.