Winter Herb Stuffed Squash

I absolutely love this dish!  And its so versatile, use whatever you like pairing with the sweetness of butternut squash.  Mushrooms would be great, certainly sage makes a great partner.  I've added some whole wheat breadcrumbs to these but that is purely optional.  Prepared quinoa would be a good addition or substitute, this would make it heartier and would be a great entree served with a salad or rapini.
I hope you enjoy this as much as I do!

serves 4
1 medium sized butternut squash
1/2 cup red onion, diced
1 clove garlic, minced
squash pieces from cavities you will make in neck end of squash *
1 TB dried cranberries (or fresh--more tart)
1/4 cup whole wheat bread crumbs, optional
1 TB fresh thyme leaves
1 TB fresh rosemary, chopped
1 cup red onion, sliced
olive oil
salt
2 tsp balsamic vinegar

Preheat oven to 450
Cut squash approximately in half lengthwise--you will end up with the "neck" of the squash and the round portion separated.  Slice neck end in half lengthwise and create a cavity for the filling by cutting out about 1/2" of squash.  Tip: I make cuts along the length and then horizontally so I end up with cubes to be cut out of the center.  Cut the round part of the squash in half lengthwise and scoop out seeds.
In a bowl mix together red onion and next 6 ingredients.  Toss with a TB of olive oil, season with ~1 tsp salt and the balsamic vinegar. 
Toss red onion slices with olive oil and salt and place in bottom of roasting pan.  Mound some of the stuffing in/on each butternut squash section and place on the bed of onions.  Nestle some sprigs of thyme and rosemary between the squash.  Cover with a tight fitting lid.
Cook on bottom rack of oven until butternut squash begins to soften and onion browns somewhat.  Approx 35 minutes.  Uncover and move to top rack, cook until golden on top, another 5-10 minutes.