Cook fresh okra briefly in boiling salted water; drain. Blanch celery in boiling salted water.
Add bell peppers and lima beans and cook until just tender; during last 30 seconds, add corn (do not overcook), then drain vegetables. Oil a large baking dish and sprinkle with bread crumbs; add a layer of corn-bean mixture and okra.
Combine onion, tomatoes and basil; spoon layer of onion-tomato mixture over bottom layer in dish. Sprinkle with chiles and season with salt and pepper. Dot with margarine and sprinkle with bread crumbs.
Repeat layering until casserole is filled. Top with a layer of okra that has been dipped in crumbs and lightly sauteed.
Bake uncovered in preheated 300F for 1 hour.
NOTE: This can be baked in the morning and reheated slowly before serving. It tastes even better the second day.