Roscoff onions

Growing it

Plant a packet of Roscoff onion sets in an empty bed. It takes 7 h of real time to the first picking, while you cook and while the app is closed. Water it once per growth stage to bring it on (each can is worth 8% of its growing time); a sack of compost brings it on by 50%. Nothing ever wilts.

What it gives

• Onion confit: 30 portions a picking, before mastery and ornaments. Home-grown, it costs the till nothing, adds 0,30 € to the tip, and is on the menu for the day whenever your shelf holds some that morning, even before its card is bought.

Buying the seed

It is a rare seasonal seed: Monsieur Anselme's crate only has it in summer weeks, one every 2 evenings. It goes on sale once you have picked 6 harvests in all. The crate has 1 packet a day, at 4,20 € each. An everyday packet is only sold once the market has delivered the fruit it grows (or the pantry had it from the start).