Preheat oven to 375. Halve pumpkin crosswise and scoop out seeds and strings. Place pumpkin halves on a large baking sheet with the cut side facing up (like a cup). Bake, uncovered, for two hours, or until fork tender. Remove from oven and cool. Scrape pulp from shells and puree in a food processor. Add salt. Use immediately in any recipes calling for pumpkin puree or freeze for future use.