Heat a large sauce pot over high heat. Add the clams and stir for 15 seconds, then add the ½ cup white wine and cover pot with lid allowing clams to steam for 1 minute.
Remove the pot from the heat and pour the clams into a colander set over a bowl. Allow the clams to cool and remove the clams from their shells. Reserve the clams and their juices separately.
Heat a large sauce pot over medium high heat. Add the olive oil and sweat the onion for 1 minute stirring constantly. Stir in the fennel, leek and celery and cook for 2 minutes. Add the garlic and cook for a further 1 minute. Stir in the ¼ cup of white wine and cook for about 15 seconds before adding the vegetable stock and the juices from the clams.
Once the soup comes to the simmer, reduce heat to low and gently simmer for 10 to 15 minutes or until the broth has thickened slightly. Stir in the reserved clams and season with freshly ground black pepper. Ladle the hot soup into bowls and serve immediately.
Source: Curtis Stone on Biggest Loser.