American

Medium · Hot

Mushroom and Cheddar Egg Gratin

Mushrooms cooked down to half their volume concentrate into something almost meaty, then are set into a cream and egg mixture scented with thyme and poured into the gratin dish. Cheddar melts into the custard as it bakes, forming a golden, slightly crisp surface over the soft, fragrant interior. It rewards the kind of slow, attentive cooking that never rushes a crust.

Recipe by

Isabella Vance

The Project Manager

Prep

20 min

Cook

30 min

Rest

5 min

Total

55 min

Method

Caramelize the Mushrooms

Flip the mushrooms, add the garlic cloves (crushed under your knife blade, then roughly minced) and thyme sprigs. Cook for another 3 minutes until the garlic is fragrant and the mushrooms are tender but holding their shape. Remove from heat and discard the thyme stems. Set aside to cool slightly.

Prepare the Egg Custard

Check seasoning by tasting only the cooked mushroom component. Do NOT taste the raw egg custard mixture before baking.

Assemble and Bake

Remove from the oven and let rest for 5 minutes before serving. The flavors will settle and the texture will stabilize into something magnificent.

Prepare and Bake

Preheat oven to 350°F (175°C). Prepare a water bath by placing the baking dish in a larger pan filled with hot water halfway up the sides.

Spread the caramelized mushrooms evenly in a lightly greased baking dish.

Pour the egg custard mixture slowly over the mushrooms.

Sprinkle the cheddar crust mixture (cheddar, softened butter, flour) evenly over the top.

Bake for 25-30 minutes until the top is golden and bubbling, and the custard reaches 170-175°F internal temperature.

Remove from the oven and water bath. Let rest for 5 minutes before serving.

Nutri-Score

Needs balance

A–E · lower is better · score 12

Calories

502

per serving

High in saturated fat · 20gSource of protein · 24gLow sugar · 4g

Protein

24g

Carbs

10g

Fat

42g

Sat. fat

20g

Fiber

Sugar

Sodium

982mg

Lacto Ovo VegetarianHeart Health ConcernHigh Saturated FatWeight ManagementLow Carb CompatibleAnti InflammatoryHigh ProteinLow CarbModerate Sodium

Nutri-Score is a general nutritional-balance guide, not medical or dietary advice.

Environmental impact

Moderate impact

A–E · lower is better · includes estimates

kg CO₂e

1.6

per serving

CCarbon

Cheddar Cheese drives 55% of this recipe’s estimated footprint.

Carbon from Poore & Nemecek 2018; water, land & runoff from Agribalyse — modelled averages for comparing recipes, not a measurement of your groceries.

Flavor Profile

Umami

Sweet

Salty

Sour

Bitter

Spicy

Textures

CreamyCrispySilkyTender

Aromas

EarthyHerbalNuttyUmami Rich

Kitchen Equipment

Primary Tool

Oven

Oven Chef Knife Cutting Board Mixing Bowl Whisk Spatula Measuring Spoons Baking Dish Plastic Wrap Parchment Paper

Counter FootprintLarge

Techniques

Sauteing Caramelization BakingEgg Custard Preparation

Safety & Storage

Cooking Temperature

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High Risk Population

Egg custards pose listeria and salmonella risks for pregnant women, elderly, and immunocompromised individuals. Ensure thorough cooking to 165°F.

Storage

Refrigerate any leftovers within 2 hours. Egg-based dishes spoil rapidly and should be consumed within 3 days.

Handling

Temper eggs slowly when combining with cream to prevent curdling. Add warm cream to eggs gradually while whisking constantly.

Cross Contamination

Use separate cutting boards for mushrooms and proteins. Wash hands thoroughly after handling raw eggs.

Equipment Safety

Use water bath (bain-marie) when baking to prevent rapid temperature spikes that can cause custard to overcook or curdle.

Pro Tips

Technique

Do not rush the mushroom sauté. Let them cook undisturbed for a few minutes between stirs — this allows them to caramelize rather than just steam in their own released moisture. Patience here translates directly to depth of flavor.
When preparing the custard, pour it over the mushrooms slowly. This gives the eggs and cream time to settle without disturbing the mushroom layer, ensuring an even, silky result throughout.

Substitution

Aged Gruyère works beautifully in place of the cheddar for a more nuanced, nutty crust. If you want something sharper, try a aged white cheddar or a blend of the two.

From the chef

There is something almost meditative about the way mushrooms surrender their moisture, collapsing slowly into butter until they turn golden and deeply savory. This gratin asks you to slow down — to let the custard set gently, crowned with cheddar that blisters just so in the oven's heat. It is the kind of dish I return to on quiet Sundays when I want to coax ordinary ingredients into something quietly magnificent.

Isabella VanceThe Project Manager

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TagsComfort FoodGratinBakedCheese

AllergensMilkEggsGluten

Source: generated · May 30, 2026