For the lasagna assembly:
1 pack no-boil lasagna sheets (GASP, a shortcut!)
2 small sweet potatoes, peeled and sliced thinly
2 lbs kale (mixed is OK), blanched, drained, and chopped finely
1 lb sweet italian sausage, no casing, pan fried and set aside
2 large leeks sliced thinly and cooked at medium low heat in fat from sausage
Bechamel sauce for white lasagna
1/2 C flour
1/2 tsp nutmeg
1/2 tsp garlic powder or 1 clove fresh garlic
3 3/4 C milk
1 C chicken or vegetable stock
2 eggs, beaten
1/2 C marsala
1 C mixed grated cheese such as parmesan, pecorino, fontina, gruyere
salt & pepper
Melt the butter. Once it reduces spitting/bubbling, add flour and whisk, cooking for 3 minutes at medium heat. Slowly add the milk and the stock, raising heat to high. Bring to a boil, stirring constantly, until sauce coats the back of a spoon. Set aside to cool until warm to touch.
Once warm to touch, add the beaten eggs, 1/2 C marsala, 1/2 C of cheese and salt & pepper to taste.
Assemble the lasagna
Preheat oven to 375. Pour a thin layer of bechamel sauce on the bottom of your lasagna pan (preferably 8×10 or something similar/bigger), add two layers of lasagne sheets. Spread the sausage evenly, add salt & pepper, and cover with more sauce.
Add another 2 layers of lasagna sheets, next adding the kale. Top with salt & pepper, sauce, and more lasagna sheets.
Add a thin layer of leeks, and then as if making a gratin spread the sweet potato slices in a single overlapping layer.
Add more salt & pepper, sauce, and the final layer of lasagna sheets. Top with sauce and remaining cheese. Bake for 40 minutes to 1 hour.