1. Heat oil in a 3-quart soup pot over high heat until hot. Add turnips, celery, onion, leek, and carrot. Stir the vegetables around until they begin to cook but don't turn brown.

2. Add water to stock pot. Bring to a boil. Reduce heat to simmering and cook until the vegetables are very soft, about 2 hours. Remove pot from heat. Let cool. Strain and discard the vegetables.

3. Store the cooled and strained stock in an airtight container in the refrigerator. It also can be stored in small quantities in the freezer for up to 3 months.