I found one of these types of squash at the local food co=op this past weekend and had no idea what I was getting, but I was hungry for squash so I thought I'd buy it and figure out what to do with it later!  When I got home I started looking for information online and the link below seemed to have the most conclusive stuff I could find.  It really was delicious and I loved having the oven on because it helped to warm the house all morning!  I ate it with some butter and a little sea salt, along with some steamed, buttered broccoli and cauliflower, and I had a chunk of left over roast beef with some of my homemade mustard, and a glop of cottage cheese on my plate. What a yummy, nourishing lunch!

BUT - - - I cannot figure out why anyone would take the risk of cutting a hard rind squash with a saw or a butcher knife. It boggles the mind. Just toss the thing in the oven for about 5-8 minutes, take it out and let it cool, and the rind will be soft enough to cut with a knife (I always use a kitchen cleaver for everything whether it's hard or soft because that is my go-to kitchen utensil) and if the rind isn't soft enough yet, throw it back in the oven until it is. Usually the inside isn't warm yet, just the rind.

This is the way I've been doing it since my grandmother taught me to do this back in the 1950's when I was first starting to learn to cook as a young girl. She also taught me not to season it until after it's done cooking and ready to eat. Another tip she gave me was to start the roasting process with the flesh side down, and about halfway through the cooking, to turn it right side up and fill the "bowl" part with a bit of real butter after poking a few holes in it with a fork so the butter will soak in.

She used lard on the pan while roasting hers, of course, because there were no fancy oils and stuff back then. I usually use natural parchment paper on the pan, or I use a graniteware roaster with just a bit of water in the bottom. It's ok if some of the butter ooozes out and gets mixed with the water, too.

https://theproducesavant.blogspot.com/2013/02/choose-kabocha.html