Filling: Heat oil in a large pan or Dutch oven. Add onion, cumin and thyme and saute over moderately high heat for about 5 minutes, stirring frequently, until onions color a bit. Add lima beans and continue cooking over high heat another few minutes; add garlic, celery, bell pepper,cilantro stems and chili powder. Cook 3minutes, then add tomatoes and water; season with salt and pepper. Lower heat, cover pan and simmer 15 minutes. When beans are tender, add corn and stir in pureed chipotle. Turn off heat. Crust: Preheat oven to 375 degrees.Bring water to aboil. Add salt and pour in cornmeal in a steady stream, whisking constantly. Cook, stirring frequently at first, until cornmeal is cooked, about 30 minutes.Stir in ground chile or chili powder. Lightly oil a 9by 33 cm baking dish and pour inabout two third of the cornmeal mixture.Let set about 5 minutes to firm. Spoon vegetables over cornmeal mixture. If cornmeal is too thick to pour,thin with warm water. Set casserole on a tray and bake until bubbling, about 25 minutes. Per serving: 319 cal; 9 g prot; 6 g fat; 56 g carb; 0 chol; 957 mg sod; dozen g fiber; vegan. Vegetarian Times, Nov 93/MM by DEEANNE