If you’re craving a hearty, flavorful, and cheesy meal, look no further than this Portobello Penne Pasta Casserole. Loaded with tender portobello mushrooms, creamy mozzarella cheese, and a savory béchamel sauce, this dish is the perfect blend of comfort food and sophisticated flavor. Whether you’re making it for a cozy family dinner or serving it at a potluck, this casserole is sure to impress.
Why You’ll Love This Recipe
- Vegetarian-friendly: While this recipe doesn’t include meat, it’s incredibly satisfying, thanks to the meaty texture of portobello mushrooms and the rich, creamy sauce.
- Quick and easy: With a total prep and cooking time of just 40 minutes, it’s an ideal weeknight meal.
- Great for leftovers: The flavors in this casserole only get better as they sit, making it a perfect make-ahead meal or next-day lunch option.
Ingredients Breakdown
Here’s everything you’ll need for this delicious Portobello Penne Pasta Casserole:
- 1 (8 oz) package uncooked penne pasta: The base of this dish, perfectly al dente pasta that holds up well in the creamy sauce.
- 2 tbsp vegetable oil: Used to sauté the mushrooms until they’re tender and flavorful.
- ½ lb portobello mushrooms, thinly sliced: These meaty mushrooms bring a savory, umami flavor to the dish.
- ½ cup butter or margarine: Forms the base of the béchamel sauce, adding richness.
- ¼ cup all-purpose flour: Helps thicken the sauce to a creamy consistency.
- 1 large garlic clove, minced: Adds aromatic flavor to the dish.
- ½ tsp dried basil: A simple herb that adds a touch of freshness.
- 2 cups milk: Creates the creamy béchamel sauce that holds everything together.
- 2 cups shredded mozzarella cheese: Adds gooey, melty cheesiness throughout the casserole.
- 1 (10 oz) package frozen chopped spinach, thawed: Adds a nutritional boost and balances the richness of the dish.
- ¼ cup soy sauce: A secret ingredient that deepens the umami flavor and adds a touch of saltiness.
Kitchen Equipment You’ll Need
- Large pot for boiling pasta
- Medium skillet for sautéing mushrooms
- Whisk and spatula for stirring the sauce
- 9×13 inch casserole dish
- Oven preheated to 350°F
Step-by-Step Instructions
1. Preheat the Oven
Start by preheating your oven to 350°F (175°C). Grease a 9×13 inch casserole dish to prevent sticking.
2. Cook the Penne
Cook the penne pasta according to the package directions until al dente. Be sure not to overcook it, as it will continue to soften in the oven. Drain the pasta and set it aside.
3. Sauté the Mushrooms
In a medium skillet, heat the vegetable oil over medium heat. Add the sliced portobello mushrooms and sauté until they become tender and most of the liquid has evaporated. This usually takes about 5-7 minutes. Once done, set the mushrooms aside.
4. Prepare the Béchamel Sauce
In a large pot, melt the butter or margarine over medium heat. Add the minced garlic and sauté for about 1 minute, or until fragrant.
Next, stir in the flour and dried basil, cooking for about 1 minute to remove the raw flour taste. Gradually add the milk, whisking constantly to prevent lumps from forming. Cook the sauce for about 5 minutes, or until it has thickened to a creamy consistency.
5. Add Cheese and Spinach
Once the sauce has thickened, stir in 1 cup of shredded mozzarella cheese. Keep stirring until the cheese has melted into the sauce, creating a smooth, cheesy mixture.
Afterward, mix in the thawed and drained spinach, followed by the soy sauce for an extra burst of savory flavor.
6. Combine Everything
Add the sautéed mushrooms to the béchamel sauce, stirring to combine. Finally, fold in the cooked penne pasta, ensuring that everything is evenly coated with the creamy sauce.
7. Bake
Transfer the pasta mixture into the greased casserole dish. Top it with the remaining 1 cup of shredded mozzarella cheese. Bake the casserole in your preheated oven for about 20 minutes, or until the cheese is melted and bubbly.
8. Serve
Allow the casserole to cool for a few minutes before serving. You can garnish it with fresh basil or parsley if you want to add a pop of color and freshness.