a large stockpot and blender; 12 small teacups or demitasse cups
In a large stockpot, heat the oil over medium heat. Add the asparagus, celery and onion and cook, stirring occasionally, until tender, about 10 minutes. Add the vegetable stock and bay leaf and bring to a boil, then reduce the heat and simmer for 30 minutes. Add the cream and simmer for another 10 minutes. Remove and throw away the bay leaf. Season with salt and pepper.
Add the spinach to the soup and let wilt for about 1 minute. In batches, pour the soup into a blender and blend on high until smooth. (Alternatively, use an immersion blender and puree in the pot.) Stir well before transferring to 12 small teacups and serve hot.
When blending hot liquid, first let it cool for five minutes or so, then transfer it to a blender, filling only halfway. Put the lid on, leaving one corner open. Cover the lid with a kitchen towel to catch splatters, and pulse until smooth.