Introduction

Enjoy all the flavors of a classic mushroom and Swiss burger in a comforting casserole form. This hearty dish layers savory beef, sautéed mushrooms, and melted Swiss cheese for a meal that’s perfect any night of the week.

A close-up of a white baking dish filled with a creamy two-layered mushroom casserole; the bottom layer is a soft, light beige potato or pasta base mixed with small mushroom pieces, and the top layer is a thick, bubbly, golden brown melted cheese with whole cooked mushrooms scattered on it, garnished with small green parsley leaves, all set on a white marbled surface. photo taken with an iphone --ar 4:5 --v 7

Ingredients

1 lb Ground Beef (can be swapped for ground turkey, chicken, or plant-based meat)
1 Onion (yellow onion or shallots work well as substitutes)
8 oz Mushrooms (crimini or button mushrooms can be used interchangeably)
3 cloves Garlic (use fresh garlic for best results)
1 cup Beef Broth (chicken broth can be used for a lighter flavor)
1 tbsp Worcestershire Sauce (essential for a savory kick)
2 tbsp Soy Sauce (adjust quantity for lower sodium versions)
1 tbsp Dijon Mustard (complements the rich flavors)
6 oz Swiss Cheese (cheddar, mozzarella, or any melty cheese can be used as alternatives)
1 cup Sour Cream (Greek yogurt can be used as a healthier option)
4 pieces Hamburger Buns (gluten-free buns can be used for a gluten-free version)
2 tbsp Olive Oil (adds richness to the dish)
Salt to taste (essential for seasoning)
Pepper to taste (essential for seasoning)
1 tbsp Fresh Parsley (optional garnish for freshness and color)

Instructions

Step 1: Preheat your oven to 350°F (175°C) to ensure it’s hot and ready for baking.
Step 2: Heat olive oil in a large skillet over medium heat. Add the ground beef, breaking it up with a spatula, and cook until browned and cooked through, about 5-7 minutes. Season with salt and pepper, then remove from the skillet and set aside.
Step 3: In the same skillet, cook chopped onions and sliced mushrooms until softened, about 5-7 minutes. Add minced garlic and sauté for another minute until fragrant.
Step 4: Return the cooked beef to the skillet. Stir in Worcestershire sauce, soy sauce, Dijon mustard, and beef broth. Let the mixture simmer for 5 minutes. Remove from heat and gently fold in the sour cream.
Step 5: Cube the hamburger buns and arrange them evenly at the bottom of a casserole dish. Pour the beef and mushroom mixture over the bread cubes, spreading it out evenly.
Step 6: Sprinkle shredded Swiss cheese on top. Bake in the preheated oven for 25-30 minutes until the cheese is melted and golden brown.
Step 7: Remove from oven and garnish with fresh parsley before serving.

Tips & Variations

For a lighter version, substitute sour cream with Greek yogurt and use ground turkey or chicken instead of beef.
Try different cheese varieties like cheddar or mozzarella for a different flavor profile.
Use gluten-free hamburger buns to make this casserole suitable for gluten-sensitive diets.
Adding a splash of balsamic vinegar to the mushroom mixture can enhance the savory depth.

Storage

Store any leftover casserole in an airtight container in the refrigerator for up to 3 days. To reheat, warm it in the oven at 350°F (175°C) until heated through, or use a microwave for a quicker option but watch to prevent drying out.

How to Serve

A close-up of a white ceramic baking dish filled with a creamy mushroom casserole. The dish has three visible layers: the bottom layer is a smooth, light cream sauce mixed with soft mushroom pieces; the middle layer consists of cooked, slightly browned whole mushroom slices; and the top layer is melted creamy cheese browned to golden on the raised parts, sprinkled with fresh green parsley leaves scattered throughout. The edges of the casserole show a bubbly, slightly toasted texture under the cheese. The dish sits on a white marbled surface with blurred whole mushrooms in the background. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I make this casserole ahead of time?

Yes, you can prepare the casserole up to the point before baking, cover it, and refrigerate for up to 24 hours. When ready, bake as directed, possibly adding a few extra minutes to the baking time.

Is it possible to freeze this casserole?

This casserole can be frozen before baking. Wrap it tightly with foil or plastic wrap and freeze for up to 2 months. Thaw overnight in the refrigerator before baking as instructed.