Meat stuffing: I used about 1 lb of ground pork. I mixed in shallot (1 medium, finely chopped), garlic (1 fat glove finely chopped), fresh parsley (1 tsp, finely chopped), dried oregano (1/4 tsp), dried basil (1/4 tsp), black pepper (1/4 tsp) and salt (1/2 tsp), Japanese "panko" bread crumbs (about 1/2 cup), and egg (one large, beaten) and kneaded it by hand until it became a bit sticky and well mixed.
Sauce: I quickly made my marinara sauce from garlic (4 cloves finely chopped) and canned whole plum tomatoes (the tomatoes from 2 cans (8 oz. each) crushed into small chunks). I cooked the garlic in olive oil (3 -4 tbs) until fragrant (1 minute) and added the tomatoes with the juice and turned the heat to simmer. I added salt, black pepper (to taste), bay leaves (2) and dried oregano and basel. After simmering for 5 minutes I tasted it and added sugar (1/4 tsp, optional) to cut the acidity.
Assembly: I stuffed the squash cavities with the pork mixture and spread the sauce over and around the squash (above lower left). I placed slices of fresh mozzarella cheese on top and baked it in 350F convection oven for 40 minutes (above lower right).
I served this with a chiffonade of fresh basel leaves. The squash was still a bit hard! I thought baking it for 40 minutes would make this giant squash soft but I was wrong. I should have pre baked or pre-cooked it. We only tasted small portions. The next day, I added a bit more sauce and a mixture of shredded aged cheddar and Mozzarella cheese and re-baked it for another 30 minutes in a 350F oven. This time, the squash was soft. Of course, you could stuff the squash with your favorite uncooked Italian sausage (out of its casing). This tasted pretty good especially with red wine. Since I did not have suitable Italian reds handy, we went for Califronia Cab Ridgeline 2004 from Alexander valley with this dish.