Saute leeks in oil for 5 minutes. Add potatoes, turnips, carrots, squash, and celery. Sprinkle with salt and pepper. Saute for 10 minutes. Add dashi or broth. Bring to a boil and cook over medium heat for 20 minutes. Add chile pepper and stir in well. Serve with sprouts sprinkled on top and stir in some sour cream if desired.