A 20-minute stint in a pan can work wonders on ordinary white onions, turning them into a wondrous, meltingly sweet base for so many things – not least in this moreish gratin. If you use jarred chickpeas, with their extraordinarily tender texture, this is a one-pan dish, and you need do no more than tip them in towards the end, before flashing the dish under the grill. Tinned chickpeas need a little more help (I outline both methods below). This is one for a cold night, with a big glass of red wine.

Spicy chickpea gratin with melted onions and kale

Prep 15 min
Cook 30 min
Serves 2-3

2 tbsp butter
1 tbsp olive oil
2 large or 3 medium onions, peeled and thickly sliced
2 garlic cloves, peeled and finely grated
1 x 700g jar chickpeas, drained and rinsed, or 2 x 400g tins chickpeas, drained and rinsed
350ml hot vegetable stock (only if using tinned chickpeas)
3 heaped tbsp rose harissa
100g kale, spring greens or spinach, shredded
150ml double cream
Salt and black pepper
Juice of ½ lemon
70g cheddar, grated
50g white or panko breadcrumbs

Melt the butter with the oil in a large, shallow casserole dish or frying pan – ideally an ovenproof one that you can stick under the grill later. Add the onions and garlic, partially cover with a lid and soften over a low-medium heat, stirring frequently, for 20 minutes.

If you’re using jarred chickpeas, do nothing with them yet; if you’re using tinned, pop them in a saucepan with the hot vegetable stock and harissa, bring to a boil, then simmer briskly, stirring occasionally, for 15 minutes, until the liquid has reduced.

Once the onions have cooked for 20 minutes, heat the grill to high (mine reads 200C). Tip the kale (or whatever greens you’re using) on top of the onions, add a good splash of just-boiled water (about 100ml), then cover and leave the greens to steam for five minutes. Stir in the chickpeas (either jarred or tinned and cooked), the harissa, if using jarred chickpeas (if you’ve used tinned, you’ll have already used it) and double cream, then taste, adjust the salt as needed and add a squeeze of lemon juice. If you’re using an ovenproof pan, scatter the cheese and breadcrumbs directly on the top, otherwise transfer the mixture to a shallow ovenproof dish before topping with the cheese and crumbs.

Flash the gratin under the hot grill for five minutes, making sure to turn the dish halfway through if you know your grill heats unevenly (mine is hotter at the front). The gratin is ready when it’s golden brown and bubbling. Serve hot with good bread on the side if you wish.