How to Make It
In a large bowl, combine the Castelfranco leaves with 3 tablespoons of the olive oil, the fish sauce and lemon juice and toss to evenly coat the leaves.
In a large skillet, heat the remaining 2 tablespoons of olive oil until shimmering. Add the Castelfranco and cook over moderately high heat, stirring, until golden in spots and just wilted, about 2 minutes. Stir in the white balsamic vinegar.
Transfer the Castelfranco to plates and top with the cheese. Drizzle with the vincotto and serve with lemon wedges.
Castelfranco is a mild member of the radicchio family. It has pale yellow leaves with red speckles.