The shopping list writes itself when you confirm the event

Why writing it by hand goes wrong

Three events in a weekend, each with its own menu, each sharing half its ingredients. Done by hand, you either shop three times or sit down with a calculator and a pen. Both are how a kitchen ends up with nine kilos of shallots and no cream.

The list is a calculation, and the inputs already exist: the menu, the recipes, the headcount and the stock.

What happens

1. Confirm the event. The list is written from the menu's recipes, scaled to the guest count.
2. Ingredients combine across events. Butter needed by three jobs on the same weekend is one line, not three.
3. Stock is netted off. What you already have does not go on the list.
4. Suppliers are suggested from the inventory line for that ingredient, where one exists.
5. Ask for a period. The week or the month, aggregated, rather than event by event.
6. Send it to vendors, split by supplier — ordering a week's food is one decision per supplier.

Units, handled honestly

Quantities convert where a conversion is real — kilos and grams, litres and millilitres. Where two units cannot be reconciled they stay separate lines and are flagged, rather than being added into a number that looks right and is not.