Rub fish with lemon juice, salt and pepper. Let stand 10 minutes. Blend cilantro, cumin, paprika, cayenne, saffron, garlic and oil and lemon juice. Coat fish in this mixture. Refrigerate for 1 hour. Add fish to a baking dish, sprinkle with celery, tomatoes and parsley. Bake in 400 degree oven for 30 minutes. Serve.