Mushroom farms supplying the hotels, since most are still imported

A first step

Grow a few bags of oyster mushroom in a shed or spare room. Meanwhile ask the purchasing managers of three hotels which mushrooms they buy, how much a week, and what they pay. When the first harvest is ready, deliver a free box to each kitchen with a weekly price attached. A standing weekly order from any one of them is your proof.

Who pays first

A hotel kitchen that buys imported mushrooms every week and would rather have fresh local ones delivered the day they are picked.

What leaves today

Hotels import mushrooms that can be grown indoors on the island, so the money for a daily ingredient leaves every week.

The idea and the mechanism are from the book. The first step was written for this site as a suggestion; if you know a better one, say so.

The test

Does it keep value that now leaves the island, or build the proof that lets somebody else do so?

The only test any idea on this site has to pass. The four rules that go with it are here.

In the book

• Ch. ElevenThe Mechanisms
  Denmark's co-operative dairies and the binding contract that held them

More from cluster 14

• 271A farmers' co-operative dairy in the hill country selling cheese and yoghurt under its own brand
• 272Buffalo-milk mozzarella and ghee for the hotels and for export
• 273Fruit and vegetable drying: mango, pineapple, papaya, jackfruit and okra as premium snacks and soup mixes for Europe and the Gulf
• 274Frozen tropical fruit pulp for the smoothie chains of the world
• 275Heritage rice varieties grown under contract and sold at ten times the commodity price
• 276Organic certification services for smallholder groups, shared so the cost is bearable

All 25 ideas in this cluster