Fontina cheese from the alpine reaches of the Valle d’ Aosta, Italy’s smallest region, is traditional for this dish, but fontal—in effect, non-appellation fontina—may be substituted.
- 10 oz. Fontina or fontal, rind trimmed, cut into small dice
- 1 cup milk
- 4 tbsp. butter
- 4 large egg yolks
- Put cheese and milk into a small bowl (add more milk if necessary to just cover cheese), cover, and set aside overnight.
- Bring water in the bottom half of a double boiler to a simmer over medium heat. Put butter into top half of double boiler. When it has melted, stir in cheese and milk until cheese has melted.
- Add egg yolks to cheese mixture one at a time, whisking constantly with a small whisk, until sauce is smooth, thick, and glossy, about 10 minutes. Pour the fonduta into a warm serving dish and serve immediately.