Celery and Tomato Pasta Sauce

The aroma of celery, a zephyr-like presence, has a background role in many preparations, from vegetable soups to risottos to stuffings to stews, but in this Roman sauce it gets an up-front opportunity to display all its considerable charm. There is a greater concentration of fragrance in the leaves than in the stalks alone, an important consideration when using American celery, whose scent is usually more muted than that of Italian varieties. To achieve the aromatic intensity I was looking