Soften the onion and garlic in oil until light and translucent.
Add leeks, potatoes and celery and simmer covered for a few minutes, then add the vegetable stock and salt and pepper to taste.
Bring to a boil, then lower the heat and let it cook with a soft boil, covered, for 20 minutes or until all the ingredients are just soft enough when pierced with a knife. Do not overcook!
Allow to cool down before puréeing in blender.
Note: I always make my soups either the day before or at least in the morning for an evening serving: It allows all the flavors to blend together and gives me the time to adjust the seasoning.
It is an inexpensive, quick, easy and elegant soup to make and it has, at the end, a beautiful light green color and a wonderful aroma. Sit yourself in front of the fireplace, close your eyes and you will forget, with the first spoonful, that spring is still unimaginable.
Note: Don’t throw away the leeks darker leaves: Keep them refrigerated until you are ready to make your next vegetable bouillon: They will add a great taste to your stock!