Place squash halves on a microwave-safe plate; cook in the microwave for 10 minutes. Remove peel and seeds. Place cooked squash flesh in a food processor and puree.

Melt margarine in a large saucepan over medium-high heat; add mushrooms and onion. Cook 1 to 2 minutes. Stir in flour and curry powder, cook 5 minutes more. Gradually stir in chicken stock and wine. Cook until smooth and slightly thickened, about 5 more minutes. Whisk in cooked squash, honey, and nutmeg. Reduce heat and simmer 15 minutes.

Stir cream into soup and reheat if necessary.