Creamy Mushroom Au Gratin

Why You’ll Love This Recipe

I love how this recipe combines earthy mushrooms with the richness of cream and cheese. The Gruyère adds a nutty depth, while the Parmesan sharpens the flavor just enough. It’s warm, comforting, and totally satisfying. Plus, it only takes about 40 minutes from start to finish, making it perfect for pairing with roasted chicken, steak, or as a stand-alone vegetarian option.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

• 1 lb cremini or white mushrooms, sliced

• 2 tbsp unsalted butter

• 1 cup heavy cream

• 1/2 cup grated Parmesan cheese

• 1/2 cup shredded Gruyère or Swiss cheese

• Extra grated Parmesan and Gruyère for topping

• 2 cloves garlic, minced

• 1 shallot, finely diced

• 1/2 tsp dried thyme

• 1/4 tsp freshly ground black pepper

• Salt, to taste

Directions

1. I preheat my oven to 400°F (200°C) so it’s ready to go when I finish the sauce.

2. In a skillet over medium heat, I melt the butter and sauté the mushrooms until softened and lightly browned, about 5–7 minutes.

3. I stir in the diced shallot and minced garlic, cooking for another 1–2 minutes until the mixture becomes fragrant.

4. I pour in the heavy cream and add Parmesan, Gruyère, dried thyme, salt, and pepper. I stir everything together and let it simmer gently for 3–4 minutes, until the sauce begins to thicken.

5. I transfer the mixture into a small baking dish, spreading it evenly.

6. I sprinkle extra Parmesan and Gruyère over the top to create a bubbly, golden crust.

7. I bake the dish for 15–20 minutes, or until it’s golden on top and bubbling around the edges.

8. I let it rest for a few minutes before serving, so the sauce can set slightly and become even creamier.

Servings and timing

This dish serves 5 and takes about 40 minutes total—perfect when I want something elegant and satisfying without spending all day in the kitchen.

Variations

When I want to switch it up, I sometimes mix in sautéed spinach or chopped kale for extra greens. I’ve also used a blend of wild mushrooms to elevate the flavor. If I want a bit of crunch, I’ll top it with a mix of breadcrumbs and cheese before baking.

Storage/reheating

Leftovers store well in the fridge for up to 3 days. I reheat individual portions in the microwave or warm the entire dish in the oven at 350°F until hot and bubbly again. It holds its texture and flavor beautifully after reheating.

FAQs

Can I use a different type of cheese?

Yes, I’ve swapped Gruyère for Swiss, fontina, or even sharp white cheddar. Each adds its own twist to the dish.

Can I make this ahead of time?

Absolutely. I often prepare it up to the baking step, cover it, and store it in the fridge. Then I bake it fresh right before serving.

Can I use milk instead of cream?

I prefer cream for richness, but I’ve used half-and-half in a pinch. Milk works too, though the sauce may be a bit thinner.

What can I serve this with?

I usually pair it with roasted chicken, steak, or as a rich side for a vegetarian spread. It’s also fantastic with crusty bread.

Can I make it gluten-free?

This dish is naturally gluten-free, just make sure the cheeses and seasonings you use are certified gluten-free if needed.

Conclusion

Creamy Mushroom Au Gratin is a comforting, flavor-packed side dish that brings rich, savory goodness to any meal. I love how easy it is to make, yet it feels indulgent and special every time. Whether it’s for a holiday table or a weeknight treat, it’s a dish that never disappoints.