This soup gets all its flavor from the peas. If you can't find really sweet fresh ones, you're better off with frozen baby peas. Cold Soup Recipes
How to Make It
Bring the water to a boil in a large saucepan. Salt the water, then add the peas and bring the water back to a boil. Cook over moderate heat until very tender, about 20 minutes. Drain the peas, reserving the cooking liquid. Set aside 1/4 cup of peas.
In a food processor, combine the remaining peas with 1/4 cup of the olive oil and 1/4 cup of the reserved cooking liquid and puree until smooth. Work the puree through a fine sieve into a large bowl. Discard the contents of the sieve. Stir in about 4 cups of the cooking liquid and season with salt and pepper; add more cooking liquid if necessary to make a nice, creamy soup. Refrigerate the soup until cold, at least 2 hours.
In a large skillet, melt the butter in the vegetable oil. Add the diced bread and brown the cubes on all sides over moderately high heat, 3 to 5 minutes. Drain the croutons on paper towels.
Ladle the cold soup into bowls and garnish each with a few of the croutons and reserved peas. Drizzle with olive oil, sprinkle with pepper and serve.