Cut off the top of the pumpkin and thoroughly clean out the seeds and pulp. Preheat the oven to 250 F. Brown the sausage, breaking into small pieces as it cooks. Drain grease and add onion, celery and green pepper. Cook a few minutes. Add soup mix to boiling water and cook a few minutes. Combine all ingredients and pour into the clean pumpkin shell. Replace pumpkin top and place pumpkin on a baking sheet. Bake one hour or until pumpkin is tender. Stir once halfway through. Remove pumpkin lid and serve, scooping out some of the cooked pumpkin into each bowl.