Skip to main content

Potato-Mushroom Gratin

Peer reviewed by UK recipe editorsAuthored by UK recipe editorsOriginally published 16 Jan 2026

Meets Patient’s editorial guidelines

This potato and mushroom gratin is the ultimate comforting side dish, combining earthy chestnut mushrooms with tender, thinly sliced potatoes. Layers of double cream and salty Parmesan cheese create a rich, velvety texture that pairs beautifully with the aromatic notes of fresh thyme and garlic. It is a sophisticated take on the classic dauphinoise, offering a wonderful depth of flavour and a satisfying golden crust that makes it a standout addition to any dinner table.

As a versatile vegetarian dish, it works equally well as a decadent accompaniment to a Sunday roast or as a substantial main course served with a crisp green salad. The recipe is also remarkably practical, as it can be prepared a day in advance and reheated without losing its luxurious quality. Whether you are hosting a formal dinner party or looking for a special family supper, this homemade gratin is a reliable crowd-pleaser.

In this article:

Continue reading below

Ingredients for Potato-Mushroom Gratin

  • 80ml olive oil, divided

  • 1.1kg medium Yukon Gold potatoes, peeled, cut lengthwise into 1/8-inch-thick slices

  • 1 1/2 teaspoons coarse kosher salt plus additional for mushrooms

  • 3/4 teaspoons freshly ground black pepper plus additional for mushrooms

  • 300ml (or more) double cream, divided

  • 240ml freshly grated Parmesan cheese (about 90g ), divided

  • 2 tablespoons chopped fresh thyme

  • 6 garlic cloves, thinly sliced

  • 350g fresh crimini (baby bella) mushrooms, sliced

How to make Potato-Mushroom Gratin

Preheat oven to 191°C. Brush 13x9x2-inch glass or oval ceramic baking dish with 2 tablespoons oil. Arrange 1/3 of potatoes, slightly overlapping, in dish. Sprinkle with 1/2 teaspoons coarse salt and 1/4 teaspoons pepper. Pour 80ml cream over; sprinkle with 30g cheese. Repeat layering 1/3 of potatoes, 1/2 teaspoons salt, 1/4 teaspoons pepper, 80ml cream, and 60ml cheese 2 more times. Bake uncovered until potatoes are tender, adding cream by tablespoonfuls if dry, about 45 minutes. Remove from oven; maintain oven temperature.

Sprinkle thyme and garlic slices over gratin. Toss mushrooms in medium bowl with 3 tablespoons oil; sprinkle with coarse salt and pepper. Arrange mushroom slices atop gratin around edge of dish. Drizzle with 60ml cream; sprinkle with 30g cheese. Continue to bake uncovered until mushrooms are tender and potato edges are golden brown, about 20 minutes longer. DO AHEAD: Can be made 1 day ahead. Cool 1 hour in dish; cover and chill. Before serving, cut gratin into 10 pieces. Transfer to rimmed baking sheet. Cover with foil and rewarm in 177°C oven, 10 to 15 minutes.

Disclaimer

While every effort has been made to ensure the information is accurate and up to date, individual needs may vary and dietary requirements can differ based on personal health conditions. Always check food labels and allergen information before preparing or consuming any recipe. If you have specific health concerns, allergies, intolerances, or are following a medically prescribed diet, seek advice from your GP, pharmacist, or a registered dietitian before making significant changes to your diet or lifestyle.

Article history

The information on this page is peer reviewed by qualified clinicians.

  • 16 Jan 2026 | Originally published

    Authored by:

    UK recipe editors

    Peer reviewed by

    UK recipe editors
flu eligibility checker

Ask, share, connect.

Browse discussions, ask questions, and share experiences across hundreds of health topics.

symptom checker

Feeling unwell?

Assess your symptoms online for free

Sign up to the Patient newsletter

Your weekly dose of clear, trustworthy health advice - written to help you feel informed, confident and in control.

Please enter a valid email address

By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.