1. In a 5-quart pot, combine olive oil, sea salt and leek. Cover and cook over medium-low heat about 5 minutes, until soft. Add asparagus; cover and cook anther 5 minutes. Add chicken stock; cover and bring to boiling. Reduce heat and simmer 15 minutes. Puree soup in blender or food processor, then pass through the fine blade of food mill until perfectly smooth.