Peel and dice the butternut squash. Toss with salt, pepper, and olive oil. Place pieces on a cookie sheet covered in tinfoil with non-stick spray and roast at 400F for 40 minutes, or until squash is tender.
About 10 minutes before the squash is done, melt the butter in a Dutch oven over medium heat. Add the onions, celery, carrots, and stir for 2 to 3 minutes. Stir in the thyme and oregano.
Add the garlic and cook for an additional 5 minutes.
Add the chopped roasted butternut squash and about 1/4 of the beans with their liquid. Mash this mixture together and then add the rest of the beans to the Dutch oven.
Pour in the white wine, and add a bit of water if you think it needs to be thinner. Reduce heat to low, and simmer while you make the béchamel.
In another pot, melt the butter for the béchamel. Over medium heat, add the flour and whisk until smooth. Stir regularly until the mixture turns golden brown, about 6 to 7 minutes.
Heat the milk in a separate pan until it is just about to boil. Whisk the milk into the butter mixture until the sauce is smooth.
Bring to a boil and cook for 30 seconds longer. Remove from the heat and season with salt and nutmeg.
To assemble: Preheat the oven to 375°F.
Brush a 9-by-13-inch glass baking dish with melted butter.
Layer the ingredients in this order: béchamel, pasta, butternut squash filling, and cheese. You should make 3 to 4 layers of pasta, finishing with béchamel and 1/4 cup of the mozzarella and ricotta sprinkled over the top.
Bake in the oven for 45 minutes, until the top is golden brown and bubbling.
Remove from the oven, allow to cool for 20 minutes, slice, and serve.