Ingredients
Meat and Vegetables
- 1 pound ground beef (90% lean)
- 1/2 cup onion (diced)
- 8 ounces mushrooms (sliced)
- 1 teaspoon fresh thyme
- 3 medium russet potatoes (about 4 cups chopped)
Sauce
- 3 tablespoons butter
- 3 tablespoons flour
- 1 cup chicken broth
- 1 cup milk
- 2 teaspoons Worcestershire sauce
- 1 cup sour cream
Topping
- 2 cups Colby Jack cheese, shredded (divided into 1 cup + 1 cup)
Instructions
- Prepare Baking Dish and Preheat Oven: Preheat your oven to 400ºF (204ºC) and grease a 9 x 13-inch baking dish to prevent sticking.
- Cook Beef and Vegetables: Heat a large skillet over medium heat and add the ground beef. Cook for about 2 minutes until it begins to brown. Then add diced onions, sliced mushrooms, and fresh thyme. Continue cooking until the beef is fully cooked through and mushrooms are browned, about 8 minutes. Drain any excess grease if necessary. Transfer this mixture to a large bowl.
- Make the Sauce: In the same skillet, melt the butter over medium heat. Stir in the flour and cook for about 1 minute to create a roux. Gradually whisk in the chicken broth in small increments, ensuring no lumps form. Next, slowly add the milk while stirring. Cook the mixture until it slightly thickens. Remove from heat and stir in the sour cream and Worcestershire sauce. Season with salt and pepper to taste.
- Combine Ingredients: Add the chopped russet potatoes to the bowl containing the beef mixture. Pour the prepared sauce over it and stir well to combine everything evenly. Stir in one cup of shredded Colby Jack cheese.
- Assemble and Bake: Pour the combined mixture into the greased casserole dish. Cover the dish tightly with aluminum foil. Bake in the preheated oven for 60 minutes, until the potatoes are tender but still hold their shape.
- Add Cheese Topping and Finish Baking: Remove the foil from the casserole and sprinkle the remaining one cup of Colby Jack cheese evenly over the top. Return the dish to the oven and bake uncovered for an additional 3 minutes, allowing the cheese to melt and become bubbly.
- Rest and Serve: Remove the casserole from the oven and let it rest for a few minutes before serving to allow flavors to settle and the dish to set.
Notes
- Use 90% lean ground beef to reduce excess grease in the casserole.
- Russet potatoes are preferred for their texture after baking but Yukon Gold can be substituted.
- Do not skip draining the grease from the beef mixture to avoid a greasy casserole.
- You can swap Colby Jack cheese with cheddar if preferred.
- Covering the casserole during the initial baking prevents the potatoes from drying out.
- Let the casserole rest after baking for easier slicing and serving.
- Prep Time: 20 minutes
- Cook Time: 1 hour
- Category: Casserole
- Method: Baking
- Cuisine: American