Combine the squash and chicken broth in a 4-quart Dutch oven. Cook over medium heat until squash is tender, about 15 minutes. Using a slotted spoon, transfer squash pieces to a blender; process until smooth. Add broth to squash; set aside.

Melt butter in Dutch oven; stir in flour and curry powder.  Cook over medium heat, stirring until smooth. Add squash mixture; increase heat to medium-high and stir until soup thickens slightly. Reduce heat to low; add remaining ingredients except ham and heat through without boiling.

Garnish with ham and serve.