Caveau Gurtlerhoft, 13 Place de la Cathedrale, was recommended to us by a local for typical Alsatian cuisine. My partner had the Poelles Forestiere, an Alsatian take on Rosti, which was laced with black forest mushrooms and an abundance of local Emmenthal- and Gruyere-type cheeses. I had the Coq au Riesling, which had the proper hearty, cooked-lovingly-by-Grand-Mere flavour. The meal was of an excellent quality and superb flavour and the basic house Gewurztraminer and Riesling were highly drinkable, but the cosy atmosphere was marred by hasty service and tablecloth overlays made of white paper.
The Caveau was jam-packed with locals, either dining as romantic couples or as whole families with small children. Located down a steep flight of stairs, this restaurant is not wheelchair-accessible or stroller-friendly. Reservations are not necessary but recommended. Try to ask for a table near the back or on the "balcony" to avoid the heavy traffic in the front of this restaurant.