Trim stem and blossom ends off zucchini and cook in boiling water 7 to 10 minutes, just until crisp tender, drain. Cut each squash in half lengthwise, carefully spoon out pulp, leaving shell intact. Mash pulp and drain. Brown sausage and onion; drain. Combine all ingredients except half of cheese. Fill squash boats and bake 20 minutes at 400 degrees. Sprinkle remainder of cheese on top of boats and slip momentarily under broiler in a 9 x 13 inch pan.

Serves 4. A very good lunch or supper dish.