Potato & Mushroom Casserole with Gruyère

• total time: 45 minutes

Ingredients

Potatoes don’t get enough love in casseroles, so I’ve upgraded this dish with nutty Gruyère and earthy cremini mushrooms. It’s creamy, cheesy, and golden—a cozy comfort food classic!

Why It Works:

Russet Potatoes: Their starchy texture holds up perfectly in layers.

Heavy Cream: Adds a rich, velvety finish—no substitutes here!

Ingredients (Serves 2-3):

4 medium Russet potatoes (about 1.5 lbs / 700 g), peeled and thinly sliced (⅛ inch / 3 mm)

2 tbsp olive oil

7 oz (200 g) cremini mushrooms (or a mix of your favorites), sliced

¾ cup (200 ml) heavy cream (double cream in UK/Europe)

2 garlic cloves

5 oz (150 g) Gruyère cheese, grated

1/2 tbsp unsalted butter (for greasing the dish)

Salt, freshly ground black pepper, and nutmeg, to taste

2-3 fresh thyme sprigs (plus extra for garnish)

Directions

Prep: Preheat your oven to 400°F (200°C). Grease an 8x8-inch (20x20 cm) baking dish with 1-2 tablespoons of unsalted butter for extra richness.

Cook the Mushrooms: Heat olive oil in a skillet over medium heat. Add sliced mushrooms and sauté for 5-6 minutes until golden and tender. Season lightly with salt and pepper. Set aside.

Infuse the Cream: In a small saucepan, warm the heavy cream with garlic and thyme sprigs over low-medium heat (don’t boil). Season with salt, pepper, and a pinch of nutmeg. Simmer for 2-3 minutes, then remove from heat and discard the thyme sprigs and garlic.

Layer the Casserole:

Start with a single layer of potato slices in the buttered dish.

Pour a portion of the infused cream over the potatoes (about a third).

Sprinkle with a handful of grated Gruyère, then add a layer of sautéed mushrooms.

Repeat the layers: potatoes, cream, cheese, mushrooms, until you’ve used most of the ingredients.

Finish with a final layer of potato slices, a drizzle of the remaining cream, and a generous topping of Gruyère cheese.

Bake: Cover the dish with foil or parchment paper and bake for 15 minutes (this ensures the potatoes cook through evenly). Remove the cover and bake for another 10-15 minutes, or until the top is golden, bubbly, and the potatoes are fork-tender.

Rest & Serve: Let the casserole rest for 10 minutes before serving. Garnish with fresh thyme leaves for a pop of flavor and color.