Creamy Salsify Gratin

DIRECTIONS

• Fill a large bowl with water and add lemon juice or vinegar.
• Peel the salsify and trim the ends.
• Transfer the salsify to the acidulated water as you peel it.
• Slice the salsify 1/4 inch thick (a mandoline or food processor makes this a quick process).
• Return the salsify immediately to the water to keep it white.
• Move the oven rack to the upper third of the oven and preheat oven to 400°F.
• In a large soup pot, melt the butter.
• Add the flour and cook over moderate heat for 2 minutes, whisking constantly.
• Add the half-and-half and bring to a boil, whisking constantly.
• Cook, whisking, for about 3 minutes, or until the half-and-half is slightly thickened.
• Season with salt, pepper and nutmeg.
• Drain the salsify and pat it completely dry.
• Add the salsify to the pot and cook over moderate heat, stirring occasionally to prevent scorching, until tender, 25 to 30 minutes.
• Pour the salsify mixture into a 9 x 13 inch baking dish and sprinkle with the cheeses.
• Bake for 20 minutes, until the cheese is melted and the casserole is bubbling.
• Preheat the broiler and broil the gratin for about 5 minutes, or just until the cheese is golden and crusty.
• Let the gratin stand for 10 minutes before serving.