In a medium soup pot, heat olive oil on medium high heat. Sauté onion, celery, leek and carrot until tender. Stir in tomatoes, kale, turkey and chicken broth. Bring to a boil, and then reduce heat to a simmer. Cook for about 15 minutes. Stir in beans (with juice) or Pearl Couscous. Simmer for about 5 minutes (or until couscous is cooked.) Meanwhile, make croutons. In a bowl, toss bread cubes with olive oil, butter, salt and pepper. Spread cubes on a baking sheet and place under broiler (about 375 degrees) tossing once or twice until golden brown. Remove from broiler, but keep broiler on. When soup is done, season soup with salt, pepper and red pepper flakes. Garnish with basil.