Place the halved pumpkins flesh side up on a baking sheet, butter the flesh, and then salt and pepper the flesh. Roast in a 425 degree oven for 50 minutes.
While the pumpkin is roasting, cook the filling (the filling only takes about 20 minutes to make so you can either make it ahead of time or make it a half hour into roasting the squash so they are done at the same time). Start by melting a few TB of butter (or bacon grease makes this taste amazing!) in a pan and add the onion and cabbage with a big pinch of sea salt. Cook on medium/high heat for 15 minutes or so until the cabbage cooks down, softens, and sweetens.
Add the garlic, spinach, beef, and cinnamon cook about 5 minutes until the spinach wilts.
Add the cooked rice, combine, and then taste the mixture for sea salt and pepper and season to your taste.
Stuff the middle of the roasted pumpkin with the cooked cabbage and beef filling. Really stuff it all in there. Sprinkle cheese over the top, and bake at 425 degrees for 10 minutes to melt the cheese.