Cut off and discard upper stalks of fennel, snipping and reserving feathery leaves for garnish. Remove any wilted outer layers of fennel and discard; remove core. Finely chop remaining fennel; set aside.
In a large saucepan cook onion and garlic in hot cooking oil about 5 minutes or until onion is tender. Carefully add chopped fennel, broth, turnip, potato, carrot, and white or black pepper. Bring to boiling; reduce heat. Cover and simmer for 25 to 30 minutes or until vegetables are very tender. Cool slightly.
Meanwhile, if using, for curry croutons, in a medium bowl combine olive oil and curry powder. Add the torn bread pieces; toss until coated. Spread bread pieces in a single layer in a 15x10x1-inch baking pan. Bake in a 350 degrees oven for 15 to 20 minutes or until croutons begin to brown, stirring once.
Place one-third of the vegetable mixture in a blender container or food processor bowl. Cover and blend or process until smooth; pour into a medium bowl. Repeat twice with remaining mixture. Return all to saucepan. Stir in beans and half-and-half or light cream; heat through. Season to taste with salt.
To serve, ladle soup into four soup bowls. If desired, float a few of the curry croutons on each serving. Garnish with snipped fennel leaves. Makes 4 servings.