Zucchini Gratin
To make zucchini gratin, salt sliced zucchini and let it drain to remove excess water, then layer it in a dish with garlic, cream or a cheese sauce, and top with grated cheese and breadcrumbs. Bake at 190 °C until bubbling and golden. Salting and draining the zucchini first is essential — it's very watery, and skipping this step gives you a soupy gratin instead of a rich, creamy one. It's a great glut-buster for August zucchini.
When August arrives and the zucchini plants are producing faster than anyone can eat, the gratin is your friend. Sliced summer squash baked with cream, garlic, and cheese under a crisp golden crumb turns a glut of the mildest vegetable into a rich, cozy side that disappears fast. It’s comfort food that happens to clear the crisper drawer.
Draw out the water first
Zucchini is almost all water, and that’s the one thing that can ruin a gratin. Salt the sliced zucchini and let it drain for 20–30 minutes, then squeeze or pat it dry before assembling. (Pre-roasting or sautéing the slices does the same job.) Skip this and you get a soupy dish; do it and the gratin bakes up creamy and rich.
Cream and cheese
Layer the drained zucchini with garlic and cream — or a light béchamel — and plenty of cheese. Gruyère is classic, but sharp cheddar or a mix works. A pinch of nutmeg lifts the cream.
A golden crumb
Top with cheese and buttered breadcrumbs for that irresistible crisp, bubbling crust. Bake until deep golden.
Make it yours
- Herby: thyme, or a handful of basil layered in.
- Tomato: alternate slices of zucchini and tomato, tian-style.
- Lighter: a béchamel instead of straight cream.
- Crustier: more Parmesan in the crumb.
Let it rest a few minutes so it sets, then serve. It’s the coziest, most crowd-pleasing way to handle the summer squash mountain — and nobody will guess how much zucchini they just ate.
At a glance
Zucchini Gratin
Ingredients
Tap an ingredient to check it off
Instructions
- Slice the zucchini, toss with salt, and let drain 20–30 minutes. Squeeze or pat dry.
- Butter a baking dish. Layer the zucchini with the garlic, cream, seasoning, and most of the cheese.
- Top with the remaining cheese and the breadcrumbs tossed with melted butter.
- Bake at 190 °C for 30–35 minutes until bubbling and golden.
- Rest a few minutes before serving so it sets slightly.
Frequently asked questions
How do I stop zucchini gratin from being watery?
Zucchini is about 95% water, so it must be drawn out first. Slice the zucchini, toss it with salt, and let it sit 20–30 minutes, then squeeze or pat it dry before assembling. You can also pre-roast or sauté the slices to drive off moisture. Skipping this is the main reason gratins turn out soupy — the salted-and-drained version bakes up rich and creamy instead.
Can I make zucchini gratin ahead?
Yes. You can assemble it a few hours ahead and refrigerate, then bake when needed (add a few minutes since it's cold). Baked gratin also reheats well the next day. Because the zucchini is salted and drained first, it holds up without weeping. It's a handy make-ahead side for a dinner or barbecue when the oven has room.
What cheese works best?
A good melting cheese with flavour: Gruyère is classic and nutty, but sharp cheddar, Parmesan, or a mix all work well. Parmesan in the crumb topping adds savoury crunch. Use what you have — the gratin is forgiving. A blend of a strong flavour cheese and a good melter gives you both taste and that golden, bubbling top.