Creamy Salsify Gratin

Directions

1. 1
   Fill a large bowl with water and add lemon juice or vinegar.
2. 2
   Peel the salsify and trim the ends.
3. 3
   Transfer the salsify to the acidulated water as you peel it.
4. 4
   Slice the salsify 1/4 inch thick (a mandoline or food processor makes this a quick process).
5. 5
   Return the salsify immediately to the water to keep it white.
6. 6
   Move the oven rack to the upper third of the oven and preheat oven to 400°F.
7. 7
   In a large soup pot, melt the butter.
8. 8
   Add the flour and cook over moderate heat for 2 minutes, whisking constantly.
9. 9
   Add the half-and-half and bring to a boil, whisking constantly.
10. 10
    Cook, whisking, for about 3 minutes, or until the half-and-half is slightly thickened.
11. 11
    Season with salt, pepper and nutmeg.
12. 12
    Drain the salsify and pat it completely dry.
13. 13
    Add the salsify to the pot and cook over moderate heat, stirring occasionally to prevent scorching, until tender, 25 to 30 minutes.
14. 14
    Pour the salsify mixture into a 9 x 13 inch baking dish and sprinkle with the cheeses.
15. 15
    Bake for 20 minutes, until the cheese is melted and the casserole is bubbling.
16. 16
    Preheat the broiler and broil the gratin for about 5 minutes, or just until the cheese is golden and crusty.
17. 17
    Let the gratin stand for 10 minutes before serving.