Wash spinach well, remove any coarse stems. Cook in water just until spinach looks wilted. Drain excess water.
Place spinach in a shallow baking dish and mix with onion powder, mace, salt, pepper.
Sprinkle sole fillets with garlic, salt and parsley.
Roll up fillets and place on top of spinach.
In a saucepan, melt butter and blend in flour. Stir in half and half and simmer, stirring until sauce thickens, add in wine and salt to taste. Cook until sauce comes to a slow boil. Remove from heat and stir in parmesan cheese saving some to sprinkle on top.
Cover fish and spinach with sauce and bake for 20-25 minutes.