Gumbo Z'Herbes With Perfect Rice

Recipe Instructions * A powder made from ground sassafras leaves; available in the spice section of some supermarkets and at specialty foods stores. Heat 1 tablespoon oil in heavy extra-large pot over medium-high heat. Add ham; saute until browned, about 10 minutes. Transfer to bowl and reserve. Melt butter in same large pot over medium-high heat. Add leeks and celery. Saute until vegetables are soft, about 8 minutes. Add green onions, parsley, and garlic. Saute until onions wilt, about 2 minutes. Reduce heat to medium-low. Add file powder, oregano, and cayenne pepper. Stir 3 minutes. Add collard greens, mustard greens, watercress, spinach, and sugar. Toss to combine. Add 2 cups broth. Cover and cook until all greens are tender, stirring occasionally, about 15 minutes. Remove pot from heat. Working in batches of 2 cups, puree greens in processor, scraping down sides occasionally. Transfer puree to bowl. Heat 10 tablespoons oil in same pot over medium-high heat. Add flour; whisk until smooth. Cook until roux is peanut butter color, whisking often, about 7 minutes. Whisk in remaining 8 cups broth and bring to boil, whisking often. Add greens puree, then ham. Simmer gumbo 10 minutes to blend flavors. Season to taste with salt and pepper. (Can be made 1 day ahead. Cool slightly; chill uncovered until cold, then cover and keep chilled. Rewarm over medium heat before serving.) Mound 1/4 cup warm rice in center of each bowl. Ladle gumbo around rice. This recipe yields 10 servings.