I had this unusual savory pudding at the delightful Ristorantino di Colomba in Ferrara one chilly February evening, served as a side dish to the hearty sausage called salama. Ferrara has had a Jewish community since 1275, when the prominent Este family offered a safe haven for Jews within the city walls; the community grew in the 16th century as a haven for those fleeing the Spanish Inquisition. Sweet winter squash is a favorite vegetable in the area's Jewish cuisine, and this pudding is a Ferrara specialty, often served (without the sausage) at Yom Kippur.
Adapted from "The Country Cooking of Italy" by Colman Andrews (Fall 2011).
Bring a large pot of salted water to a boil over high heat, then add the squash, reduce the heat to medium, and cook for 20–30 minutes, or until squash is very soft.
Meanwhile, heat the butter over the lowest possible heat in a medium saucepan, then whisk in the flour. Raise heat to medium-low and continue stirring for 5–6 minutes, or until sauce turns light golden-brown. At the same time, in another medium saucepan, scald the milk (that is, bring it to just below boiling) over medium heat. Immediately pour the milk into the sauce in a slow, steady stream, whisking constantly. Increase the heat to medium-high and bring the sauce just to a boil, then reduce the heat to medium, stir in the egg yolks and cheese, and continue stirring for about 10 minutes.
Preheat the oven to 350ºF/180ºC.
Drain the squash and put it into a large bowl. Mash it with a fork or potato masher, then pour in the white sauce, stirring constantly with a wooden spoon or whisk until mixture is smooth.
Lightly grease a 2-quart/2-liter soufflé dish or pudding bowl, then pour in the squash mixture. Put it into a large ovenproof pot, then fill the pot with water halfway up the sides of the dish. Bake for 50–55 minutes, or until pudding is set and lightly browned on top.