Creamy Courgette Gratin (Gratin de Courgettes)

Name: Creamy Courgette Gratin (Gratin de Courgettes)
Prep time: 30 min
Cook time: 30 min
Total time: 60 min
Ingredients: 6 zucchini (courgettes) (sliced into 1cm rounds); Olive oil; 1 garlic clove (minced or grated); 17 fl oz semi-skimmed or whole milk; 2.75 oz butter (salted or unsalted); 2.75 oz all-purpose flour (plain flour); 3.4 fl oz heavy cream (double cream) (about scant 1/2 cup; optional); 1 oz Parmesan (grated; about 1/3 cup); 1 oz mature cheddar (grated; about 1/4 cup); 1.75 oz Gruyère cheese (grated; about scant 1/2 cup); 1 oz breadcrumbs (regular or panko; about scant 1/2 cup); Flaky salt; Freshly ground black pepper

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This recipe for a Gratin de Courgettes (the French name for a Courgette Gratin) is so delicious. It’s creamy and rich, with an oozy cheese sauce and soft, melty courgettes (zucchini). With a golden crispy top, it’s the perfect gratin. The best part, aside from how good it is, is it doesn’t take too much effort and relies on the oven to do the hard work.

gratin de courgettes in an enamel baking dish.

Why you will love this recipe
Ingredients
Substitutions and variations
How to make a delicious gratin de courgettes
Tips from Margie’s kitchen
Frequently asked questions
Other recipes you may enjoy
Creamy Courgette Gratin (Gratin de Courgettes) Recipe
Make-ahead and storage

This gratin is quite traditional, with a cheese béchamel poured over the softened courgettes, then grilled until the top is crispy. A gratin just refers to a dish with a golden, crispy top, but it can be with any filling, so you’ll often see potato gratins too. I love courgettes for their texture in this. They retain a slight bite from their skin but melt perfectly into the cheese sauce.

Why you will love this recipe

This dish is super comforting with its creamy cheese sauce and a crisp golden topping.
It’s a versatile recipe – it works as a side dish or a light main.
Make-ahead friendly – it can be prepped in advance and baked when needed.
It’s absolutely delicious with minimal effort required.

Ingredients

Courgettes (zucchini) – Green courgettes look nice here with the cheese sauce, but yellow courgettes also work. Known as zucchini in other parts of the world!
Gruyère – This is a nutty hard cheese that I love here. You can find it in most big supermarkets.
Milk – You can use semi-skimmed or whole milk. Whole will make it more luxurious, but if it’s a weeknight, you may prefer semi-skimmed.

Substitutions and variations

Cheese swaps: Gruyère gives a nutty richness, while cheddar makes it sharper. You can also try Comté, Emmental, or even a mix for more depth.

Make it vegetarian-friendly: Check your cheese labels, as some hard cheeses like Parmesan may contain animal rennet.

Lighter version: Use semi-skimmed milk and skip the cream for a slightly lighter but still creamy sauce.

Extra flavor: Add a pinch of nutmeg to the béchamel sauce, or scatter in some fresh herbs such as thyme or basil with the courgettes.

How to make a delicious gratin de courgettes

Here’s a quick visual guide — the full recipe with exact measurements is below.

ONE: Over medium heat, heat a drizzle of olive oil in a large frying pan. Add the courgettes and fry until lightly golden and softened.

Adding garlic to courgettes in a pan for gratin.

TWO: Add the garlic and cook for another minute. Transfer to a 10-inch (25 cm) diameter ovenproof dish. Preheat the oven to 375°F (190°C/170°C fan).

THREE: In a separate small saucepan, melt the butter. Once melted, add the flour and mix together. Cook for 1 minute. Then pour in the milk bit by bit, whisking as you go, to make a smooth white sauce.

FOUR: Once thickened, add the cheese, keeping some back for the top. Add the cream, season well with salt and pepper, then stir.

Pouring cheese sauce over sliced and fried courgettes.

FIVE: Pour the cheese sauce evenly over the courgettes.

Adding grated cheese to zucchini gratin.

SIX: Sprinkle with the reserved cheese and breadcrumbs. Bake for 25–30 minutes until the topping is golden and crisp, and the sauce is bubbling at the edges.

Tips from Margie’s kitchen

Slice evenly: While these don’t need to be sliced thinly as such, it’s nice if they are all even thickness, so I love my mandoline. It is one of my favorite kitchen gadgets as it makes slicing vegetables unbelievably quick and easy. Just make sure to use the guard and go slowly, as they can be very sharp and dangerous!
Make ahead: This dish can be assembled a day in advance. Prepare the courgettes and cheese sauce, layer everything in the dish, then cover and refrigerate. When ready to serve, bake as directed, adding 5–10 extra minutes to the cooking time if it’s going into the oven straight from the fridge.

Frequently asked questions

What is a gratin?

A gratin is normally any dish that is topped with cheese and/or breadcrumbs and baked (or broiled) until golden brown and crisp. Pommes au Gratin is probably the most famous version, but I love it this way with courgettes.

What do I serve with this Courgette Gratin?

This is the perfect entertaining recipe to serve with a selection of your favorite salads or as a side to something more warming and comforting, such as a roast chicken. I think this would also be a nice side dish to a roast dinner, like a Brussels sprout gratin but with courgettes!

How should I store leftover courgette gratin?

Any leftovers should be left to cool completely before covering and chilling in the fridge for up to 3 days.

Can I freeze this gratin de courgettes?

Yes, you can freeze courgette gratin. Assemble the gratin, allow it to cool completely, then cover tightly and freeze for up to 2 months. Bake from frozen at 392°F (200°C/180°C fan) for about 45 minutes, covering with foil for the first 30 minutes to stop the top from browning too quickly.