The gnocchi strips can be frozen for up to 3 days. The ragout components can be cooked up to 2 hours ahead and kept at room temperature.
Sheep's-milk ricotta is often blended with some cow's milk. It's available at specialty food stores and by mail order from Old Chatham Sheepherding Company (888-SHEEP-60 or blacksheepcheese.com). Alternatively, use cow's-milk ricotta and drain it overnight in a fine strainer in the refrigerator; discard the whey.
A full-bodied, dry but balanced California Chardonnay will frame the sweetness of the corn and tarragon in this dish.