Cheesy Kielbasa Potato Casserole

Moving from a brothy slow-cooker beef soup straight into a Cheesy Kielbasa Potato Casserole is an absolute touchdown of a comfort food pivot.

Cheesy Kielbasa Potato Casserole

• Prep time: 20 minutes
• Bake time: 45–50 minutes
• Servings: 6 to 8 hungry plates

Ingredients

• The Core Ingredients:
  • 1.5 lbs smoked kielbasa sausage, sliced into neat 1/2-inch rounds
  • 2.5 lbs russet or Yukon Gold potatoes, peeled and sliced thin (about 1/4-inch thick rounds)
  • 1 medium yellow onion, diced
• The Velvety Cheese Sauce (A Quick Mornay):
  • 1/4 cup (1/2 stick) unsalted butter
  • 1/4 cup all-purpose flour
  • 2.5 cups whole milk (or half-and-half for an even richer sauce)
  • 3 cups sharp cheddar cheese, freshly shredded (divided: use 2 cups in the sauce, 1 cup on top)
  • 1/2 tsp garlic powder
  • 1/2 tsp onion powder
  • 1 tsp salt & 1/4 tsp black pepper
  • 1 tsp Dijon mustard (the secret ingredient that makes the cheese sauce pop)

Instructions

1. Preheat and Prep:
   Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish generously with butter or cooking spray.
2. Brown the Kielbasa:
   In a large skillet over medium-high heat, brown the sliced kielbasa rounds for about 3–4 minutes per side until they develop a nice caramelized crust. Remove them with a slotted spoon and set aside. In the same skillet with the leftover sausage drippings, sauté the diced onions for 3 minutes until soft.
3. Make the Cheese Sauce:
   In a medium saucepan, melt the butter over medium heat. Whisk in the flour and cook for 1 minute to remove the raw flour taste. Slowly pour in the milk while whisking constantly to prevent lumps. Cook, stirring frequently, until the mixture thickens and bubbles (about 5 minutes).
4. Melt the Cheese:
   Remove the sauce from the heat. Stir in the garlic powder, onion powder, salt, pepper, Dijon mustard, and 2 cups of the shredded sharp cheddar cheese until completely melted and smooth.
5. Layer the Casserole:
   Arrange half of your sliced potatoes in the bottom of your prepared baking dish. Scatter half of the browned kielbasa and onions over the potatoes. Pour half of the warm cheese sauce evenly over the top. Repeat with the remaining potatoes, kielbasa, and the rest of the cheese sauce.
6. Bake to Golden Perfection:
   Cover the baking dish tightly with aluminum foil and bake at 375°F for 35 minutes (this ensures the potatoes cook all the way through).
7. The Cheesy Crust:
   Remove the foil, sprinkle the remaining 1 cup of sharp cheddar cheese over the top, and bake uncovered for another 10 to 15 minutes, or until the potatoes are fork-tender and the cheese on top is bubbling, golden brown, and slightly crisp at the edges. Let it rest for 10 minutes before serving so the sauce sets up.