Peel and roughly chop 1 large kabocha squash (about 3 pounds), discarding the seeds. Cook in boiling salted water until soft, about 20 minutes; reserve 1/2 cup of the cooking liquid, then drain. Puree the squash and the reserved liquid with 1/4 cup heavy cream; season with salt and pepper. Top with toasted pepitas.
Use a food processor or immersion blender to puree these veggies-they're too fibrous for a potato masher.