Combine all but the last three ingredients in a pot with 2 quarts of boiling water. Simmer for 1 1/2 hours.
Meanwhile, simmer the yam in lightly salted water until just tender. Drain the water & reserve the vegetables.
Allow the soup to cool slightly. Strain the stock & set aside. Puree the cooked solids & return to the pot. Add enough of the reserved stock to form a syrupy consistency. In a small pan, reduce the remaining stock until thickened & add it to the soup.
Add the salt, pepper & Scotch bonnet. Simmer for 1 hour. 5 minutes before serving, add the diced yams. Heat through & serve.
VARIATIONS: Replace the dasheen with 1 bunch of spinach.
Replace the yams with either malanga or dasheen root. Cook in the same way.
Virginie & George Ebart, "Down-Island Caribbean Cookery"