Prep 1 hr 15 mins
Cook 40 mins
Posted per request
- 2 tablespoons unsalted butter
- 1 1⁄2 lbs white button mushrooms or 1 1⁄2 lbs cremini mushrooms, cleaned and thinly sliced
- 1 (16 ounce) package frozen chopped spinach, thawed and squeezed dry
- 4 teaspoons minced fresh tarragon leaves
- 1⁄2 teaspoon grated nutmeg
White Wine Veloute
- 8 tablespoons unsalted butter, cut into small pieces
- 1 large onion, minced
- 6 tablespoons all-purpose flour
- 2 cups chicken broth
- 2 cups whole milk (do not use fat free) or 2 cups low-fat milk (do not use fat free)
- 1 cup white wine (preferably a smooth white Burgundy or a fruity Pinot Gris)
- 9 no-boil lasagna noodles
- 12 ounces emmenthaler cheese or 12 ounces gruyere, grated
- Make mushroom ragu: melt 2 tablespoons butter in a big skillet over medium heat; add in mushrooms; saute for 4 minutes, until they give off their liquid and it reduces to a glaze.
- Stir in the chopped spinach, tarragon, and nutmeg; cook/stir for 1 minute; remove from heat, cover, and set aside.
- Make white wine veloute: put cut up 8 tablespoons butter and onion in a large, cool saucepan; set over medium-low heat; as the butter melts, stir often so that the onion is coated.
- Decrease heat to low and cook until the onion is very soft, almost caramelized, and golden, stirring often, about 12 minutes.
- Cover and decrease heat even further, and cook for another 5 minutes, stirring once or twice.
- Meanwhile, position the oven rack in the center of the oven; preheat to 400°.
- Take the lid off the pan and sprinkle with flour evenly over the onion.
- Whisking constantly, cook just so the flour loses its raw taste and forms a paste with the liquid in the pan, about 20 seconds (do not brown).
- Whisk in the broth and milk in a slow, steady stream; increase heat to medium-low and continue cooking, whisking constantly, until the sauce starts to bubble and gets noticeably thicker, about 2 minutes.
- Whisk in the wine and continue simmering, whisking all the while, until thickened like a heavy cream sauce, about 2 minutes.
- Set the pan aside off the heat and give the mixture one more good whisking.
- Layer the casserole in a 13x9 inch baking dish as follows: ½ cup white wine veloute, spread across the bottom of the dish; 3 no-boil noodles, 2 cups white wine veloute, spread over the noodles with a rubber spatula; half the mushroom ragu, spread gently over the casserole, 1/3 of the grated cheese, 3 no-boil noodles, 2 cups white wine veloute; the remaining mushroom ragus; half the remaining cheese, the remaining noodles, the rest of the white wine veloute; and finally the rest of the grated cheese.
- Bake, uncovered, until bubbly and set, about 40 minutes.
- Let stand at room temperature for 5-10 minutes before serving.