Vegetables and herbs must be well washed and dried before chopping and measuring. Chopping can be done very speedily and efficiently in a food processor if desired. Accurate measuring of greens is not essential to success of this dish. Combine greens in a bowl. Mix flour with 1 teaspoon salt and pepper to taste and sprinkle over greens, then toss well. Beat eggs until frothy and pour over greens. Stir well to combine and adjust seasoning. Heat butter in a 23 cm round casserole dish or deep cake pan in a moderate oven. Swirl to coat sides and pour in egg mixture. Bake in a moderate oven, one shelf above center, for 45-50 minutes until set and top is lightly browned. If insufficiently browned when set, place briefly under a hot grill. Serve hot, cut in wedges, with yogurt and flat bread. Also good served cold. Serves 4.