I buy Brussels sprouts on the stalk and leave them there

In late autumn, Brussels sprouts appear in the shops in a way that always makes me smile: still on the stalk. A long, thick, pale green stalk covered from top to bottom in tight little sprouts, like buttons on a coat. I carry one home sticking out of my shopping bag like a club. For years, I bought loose sprouts in a net instead, and within three or four days, the outer leaves had gone yellow and the cut ends had turned brown. On the stalk, it is a different story. So I buy them on the stalk and leave them there until the day I cook them.

The reason is simple. A sprout on the stalk is still attached to the plant that fed it, and the stalk holds moisture. Cut off, a sprout starts to dry out and lose its sweetness from the cut end. On the stalk, they stay firm, green and fresh noticeably longer, often a week or more.

At home, I don't wash the stalk. Water sitting between the tight leaves makes them go soft and spotty. If the stalk is too long for my fridge, I cut it in half with a big, heavy knife on a board that doesn't slide, keeping my other hand well away. Then the halves go into the fridge, in the salad drawer or on the bottom shelf, loosely wrapped in a paper bag or a clean tea towel so they don't dry out. Any sprouts that have already fallen off, or that I have snapped off, go into a tub or a bag with a few holes and are used first.

On the day I cook them, I take off only as many as we will eat. Most come off easily with a firm push of the thumb at the base; the stubborn ones I cut off close to the stalk with a small knife. Then I trim the base, pull off any tired or yellow outer leaves, and rinse the sprouts in a colander under cold running water. Big ones I cut in half, so they cook at the same time as the small ones.

My favourite way to cook them is roasting, which turns them sweet and nutty instead of the soft, grey sprouts many people remember. I toss them on a tray with a spoon of oil and a pinch of salt and pepper, cut side down, in one layer with space between them. At 200°C (180°C fan), they take 20 to 25 minutes, until the cut sides are deep brown and the outsides are crisp. At the end, I sometimes add a little lemon zest, a few chopped toasted chestnuts, or a spoon of crispy bacon pieces. They are good next to roast meat, with a fried egg, or on their own in a bowl.

Leftover roast sprouts cool on the tray and go into the fridge, covered, within two hours. We eat them within two days, warmed in a hot pan until they are piping hot, with a little butter. And the bare stalk, once all the sprouts are gone, goes into the food waste or the compost.

If there are more sprouts than we can eat, I freeze some: three minutes in boiling water, straight into iced water, dried well on a towel, frozen on a tray and then tipped into a labelled bag. They don't stick together, and in winter I can take a handful straight onto the roasting tray.

Brussels sprouts are high in fibre, and for some people, they cause wind, so I serve a modest portion with the rest of the meal. For small children, I cut them into quarters.

Do you buy sprouts on the stalk, or loose in a bag?

Roast Brussels sprouts from the stalk. Serves 4. About 30 minutes. You need about 500 g Brussels sprouts (from a stalk), 1 tbsp olive or sunflower oil, salt and pepper, lemon zest or chopped toasted chestnuts (optional). Heat the oven to 200°C (180°C fan). Snap or cut the sprouts off the stalk, trim the base, remove tired leaves and rinse. Halve the big ones. Toss with oil, salt and pepper and spread cut side down in one layer. Roast for 20–25 minutes until deep brown and crisp. Add lemon zest or chestnuts and serve. Chill leftovers within 2 hours and eat within 2 days.