Leek gratin

Gratin – a useful dish

A vegetable gratin is a very useful dish. Let’s say you have a rather modest piece of fish to serve per diner, and you don’t necessarily want to bulk the meal out with potatoes/rice/pasta. If you serve it with a few cauliflower florets, everyone will go hungry.

But place these florets in a baking dish and swamp them in cheesy cream – cauliflower cheese at its simplest. That’s an entirely different dinner proposition! It’s filling, satisfying and positively rich. Nobody will even notice there are no carb fillers on their plate.

What exactly is a gratin?

Au gratin, from the French verb ‘gratter’ which means ‘to scrape’, is a cooking method that involves grilling or baking dishes covered with a coating or crust.

Classically that crust would be often made with cheese and/or breadcrumbs and it is often mistakenly thought to be saucy rather than crusty. Thus in my view potatoes dauphinoise, especially the recipes which tell you to simply pour cream over sliced potatoes and bake them, are not a classical gratin. Unless of course there is a topping of cheese on them, which makes them then not only a true gratin but also more delicious.

This gratin is proper: the cream mix has cheese in it, and it forms a delicious crust on top of the leeks when baked.

How to clean leeks?

I like to buy what I call proper vegetables in the market, grubby with soil or sand, with full tops and stems. Supermarket vegetables are always too sterile, too pristine, looking completely devoid of flavour. Earthy-looking potatoes are much nicer than the ones that need no washing, let alone scrubbing. Perhaps it’s the effort you have to put in that makes them tastier?

Thus the leeks that I buy are layered with sand and soil, and cleaning them requires a minute. But to make things easier, chop them first. You’ll then be able to rinse all the dirt off easily, agitating leeky flakes in a bowl of cold water.

Parboil or not?

Leeks become tender fairly quickly, especially chopped reasonably small. So you might argue parboiling them is a waste of time. And it would be true, should you wish to cook a proper béchamel to bake the leeks in.

But my recipe is for a rough and ready, easy hack of a gratin. No cooking roux is required, no adding milk by a spoonful, no stirring and stirring lest it catch to the bottom of the pan.

My gratin mix is cream, seasoning, some flour and cheese, all mixed together to dollop over the leeks, and baking au such gratin takes barely half an hour. And so it makes sense to precook the leeks, especially that it will mean an extra rinse of the vegetables.

How to make the leek gratin

Once you’ve parboiled the leeks, rinse them with cold water. That’s primarily to cool them down if you’re cooking the gratin straight away. The cheffy requirement of plunging blanched veg in buckets of icy water is a waste of time, and ice cubes are better utilised in a daiquiri.

But cooling down is important because you want to squeeze as much water from them as you can, otherwise the gratin will be soggy and watery – not a nice look as ‘scratching’ the dish is what it’s about (rather than slopping). Grab small handfuls of leeks, squeeze them out like a lemon and arrange in a buttered gratin dish.

The mustard in the cream mix sharpens the flavour rather than grants it so don’t fret if you’re not a huge fan of mustard. The dill can be swapped for tarragon or sage, and the cheese may remain blue like in my recipe or be replaced with Cheddar, Comte or Welsh Caerphilly (very fitting for leeks).

The gratin will be ready in just under half an hour, as soon as it turns suitably gratinéed (crusty) on top.

More leek recipes

Leek slaw, a simple salad of raw leeks with cucumber and radish, seasoned with black pepper and honey. Leeks are incredibly healthy when eaten raw, did you know?

Caramelised leek and Cheddar tart on shortcrust pastry, homemade or shop bought, is a fabulous, easy dish, as good to serve warm as it is cold.

Leek and potato bake, or gratin, with creme fraiche and cheese. This is a vegetarian dish which resembles tartiflette or pommes dauphinoise in its levels of comfort.

More vegetable gratin recipes

Kabocha squash gratin, a creamy, cheesy, delightfully comforting winter dish using a lesser known squash, also known as Japanese pumpkin. The recipe is thoroughly homely though: kabocha slices baked in cream and cheese flavoured with thyme.

Beetroot gratin, thinly sliced beets baked in garlic and dill infused cream, a gorgeous side to a fish course. No need to pre-cook the beetroot.

Celeriac gratin recipe with cream, garlic and grated cheese. Celeriac tastes a bit earthy and aside this dish it is suitable for a mash or puree, celeriac fondant or celeriac soup.