Ingredients
4 tablespoons unsalted butter, plus 1 tablespoon melted for dish
1/3 cup plus 2 tablespoons toasted hazelnuts, finely chopped
1/4 cup plus 2 tablespoons freshly grated Parmesan cheese
3 cups milk
1 pound Jerusalem artichokes (about 10 small), peeled, cut into 1-inch chunks, and reserved in cold water (drain and pat dry before using)
1/4 cup all-purpose flour
4 large egg yolks
2 teaspoons coarse salt
1 teaspoon finely chopped fresh rosemary
1 teaspoon finely chopped fresh thyme
1/2 teaspoon finely chopped fresh sage
5 large egg whites, room temperature
Preparation
Preheat oven to 400 degrees. Brush inside of a 1 1/2-quart souffle dish with melted butter. Add 2 tablespoons each hazelnuts and cheese to dish; rotate to coat. Set aside.
Combine milk and artichokes in a medium saucepan; bring just to a boil over medium heat. Reduce heat to medium-low; simmer, uncovered, until artichokes are tender when pierced with the tip of a paring knife, about 30 minutes. Drain in a colander set over a heatproof bowl, reserving 1 1/4 cups milk.
In a food processor, puree artichokes until smooth. Pass puree through a fine sieve into a bowl; discard solids.
Melt remaining 4 tablespoons butter in a medium saucepan over medium heat. Whisk in flour; cook, stirring, 2 minutes. While whisking, slowly add reserved milk; whisk until smooth, then whisk in puree. Remove from heat.
Whisk in egg yolks, one at a time, until smooth. Whisk in salt, herbs, and remaining 1/3 cup hazelnuts and 1/4 cup cheese.
In the bowl of an electric mixer fitted with the whisk attachment, beat egg whites to stiff peaks; gently fold into artichoke mixture and spoon into prepared dish. Bake until puffed and golden brown, about 40 minutes. Serve immediately.
