A sformato is essentially a soufflé that doesn't rise because there isn't any air or egg white whipped into it—foolproof! I serve it in place of mashed potatoes, since it has a great flavor without an excess of butter and cream. If I have people over, I'll bake it in individual gratin dishes with a few fresh thyme leaves on top for presentation's sake.
Delicata squash has a flavor similar to that of butternut, but the skin is much thinner—edible, in most cases—and the squash is more delicate overall (hence the name). The flesh of a butternut or acorn squash would be a fine substitute. Cooking with squash in the fall and early winter months will yield the best results with this recipe. I find that out of season the squash become a bit waterlogged. You can do everything but bake the sformato in advance. Bring the dish to room temperature before baking.
