Potato Gratin with Garlic, Thyme, and Cream

French

Medium · Hot

Potato Gratin with Garlic, Thyme, and Cream

A classic French bistro gratin — thinly sliced potatoes baked in a rich cream sauce infused with garlic and fresh thyme until golden and impossibly silky.

Recipe by

Claude Beaumont

The Bistro Classicist

Prep

20 min

Cook

Rest

5 min

Total

1h 25m

Method

Preparation

Preheat your oven to 190°C (375°F). Peel the potatoes and slice them thinly, about 3mm thick — a mandoline is ideal here, but a steady hand with a sharp knife will serve you well.

Bruise the garlic cloves by pressing them with the flat of your knife. This releases the oils without burning.

Infusing the Cream

In a small saucepan, combine the heavy cream, bruised garlic, and half of the thyme sprigs. Warm over medium-low heat until it just begins to simmer around the edges — do not boil. Remove from heat and let steep for 10 minutes.

Strain out the garlic and thyme, pressing gently to extract all that beautiful infused flavor back into the cream.

Assembly and Baking

Generously butter a gratin dish. Arrange a layer of potato slices, overlapping slightly, in a circular pattern.

Season lightly with salt and black pepper. Repeat with remaining potato slices, creating 2-3 layers total.

Pour the warm garlic cream evenly over the potatoes, ensuring it seeps between the layers.

Scatter the remaining thyme leaves over the top. Dot with the remaining butter, cut into small pieces — this is where the golden crust begins.

Place in the oven and bake for 55-65 minutes, until the top is deeply golden and the cream has reduced to a rich, glossy sauce. A knife should slide through the potatoes with no resistance.

Finishing Touch

Allow the gratin to rest for 5 minutes before serving. This allows the sauce to set slightly and makes plating much cleaner. The top will continue to crisp as it rests.

Nutri-Score

Good balance

A–E · lower is better · score 0

Calories

480

per serving

Low sugar · 5g

Protein

Carbs

46g

Fat

30g

Sat. fat

13g

Fiber

Sugar

Sodium

450mg

Gluten FreeContains LactoseComfort FoodIndulgenceLow Fiber

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

Environmental impact

Low impact

A–E · lower is better · includes estimates

kg CO₂e

0.6

per serving

BCarbonAEU all-round· carbon sets the grade

Water

0.1m³

Land

21Pt

Runoff

0.06g P

Heavy Cream drives 67% 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

CrispySilkyCreamyTender

Aromas

HerbalButteryEarthyPungent

Kitchen Equipment

Primary Tool

Oven

Cutting Board Mandoline Chef Knife Cutting Board Fine Mesh Strainer Gratin Dish Pastry Brush Parchment Paper Aluminum Foil

Counter FootprintMedium

Techniques

Infusing BakingResting

Safety & Storage

Allergen Warning

Contains milk allergens from heavy cream and butter. Verify all guests have no dairy allergies or lactose intolerance before serving.

Cooking Temperature

Do not boil the infused cream during preparation — bring only to a gentle simmer around the edges to prevent scalding and separation. The gratin must reach a golden-brown top at 190°C (375°F) within 55-65 minutes.

Handling

Use extreme caution when slicing potatoes with a mandoline — the blade is extremely sharp. Use the provided guard and keep fingers away from the slicing edge. Cut away from your body.
Allow the gratin dish to cool for 5 minutes before serving. The dish and cream will be extremely hot and can cause severe burns if served immediately.

Storage

Refrigerate leftover gratin within 2 hours of serving. Store in an airtight container. The dairy-based cream sauce makes this dish perishable.

Shelf Life

Consume refrigerated leftovers within 3 days. The cream-based sauce quality degrades rapidly and poses foodborne illness risk if held in the danger zone (4-60°C / 40-140°F) for extended periods.

Cross Contamination

Do not use the same cutting board for potatoes and allergen-free items without thorough sanitization between uses, especially important if preparing for guests with milk allergies.

High Risk Population

This dish contains dairy and is not suitable for individuals with milk allergies, severe lactose intolerance, or those following a dairy-free diet. Young children, elderly, and immunocompromised individuals should consume only properly heated portions.

Pro Tips

Technique

A mandoline is your friend here — those 3mm slices must be consistent, or the gratin will cook unevenly. A sharp knife works if your hand is steady, but do not attempt this with a dull blade. The potatoes will tear, and the cream will pool instead of being absorbed.

Substitution

If you insist on adding cheese — and I understand the temptation — a handful of grated Gruyère scattered between layers is acceptable. But a true Dauphinois gratin has no cheese. The beauty is in the cream alone.

Equipment

Use a proper copper or ceramic gratin dish — something with depth. A shallow baking sheet will not hold the cream properly, and you will have a mess in your oven.

From the chef

In Lyon, we say a proper gratin is not made — it is coaxed. The thin potato slices surrender their starch into that garlic-thyme cream slowly, layer by layer, until the whole dish becomes something greater than its humble parts. This is the bistro at its finest: simple ingredients, proper technique, and the patience to let butter and cream work their quiet alchemy. Trust the process, and you will be rewarded with the silkiest gratin your guests have ever tasted.

Claude BeaumontThe Bistro Classicist

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TagsVegetarian

AllergensMilk

Source: generated · June 10, 2026