Preheat oven to 375 degrees. Line a baking sheet with parchment and place squash cubes in a mound in the center. Drizzle with olive oil and season with salt and pepper. Toss to coat and spread into a thin layer. Roast for 25-30 minutes until soft.

While squash is roasting make the white sauce. Melt butter over medium heat in a medium sauce pan, add sage, garlic and rosemary and cook 3-4 minutes until butter bubbles and starts to brown. Remove sage and rosemary and set aside.

Add flour and stir, forming a roux. Slowly add milk and broth, stirring well to incorporate and thicken. Continue to add liquid a little at a time until sauce has thickened. This takes about 20 minutes.*

Season with nutmeg, salt & pepper. Add spinach and stir to combine. Add cheese and stir and cook until cheese has melted. Remove from heat.

Mash squash with the back of a spoon or fork. Combine with ricotta and season with salt and pepper.

Put a thin layer of sauce in the bottom of a greased baking dish {8″ x 8″} top with lasagna noodles or sheets, tearing to fit in 1 layer of pasta.

Top noodles with 1/2 the squash mix and 1/2 of the ham. Top this with 1/2 of remaining spinach sauce. Repeat layers.

Top casserole with Parmesan and either cover and refrigerate for up to 2 days or bake at 350 degrees for 45-60 minutes. Baking time will depend on temperature of casserole when baking.

Let lasagna rest for 5-10 minutes to set before cutting. Garnish with reserved sage leaves.