Learning to use new ingredients can be daunting, especially vegetables where the preparation and cooking techniques are unfamiliar and the guidance available is minimal. Fortunately, kabocha is fairly forgiving. I’ve settled on a reliable technique that works well and requires no additional ingredients like oil or seasonings. My typical kabochas are around 1.5 kg, so as long as yours is somewhere close to this, the timings should work well.
Preheat an oven to 400 ºF (200 ºC). Place the kabocha on baking sheet with a wire rack and roast whole for 20 minutes. Take out the kabocha and, when cool enough to handle, since it down the middle, right through the stem (this make take some strength). The point of this initial roast is to soften the kabocha so it’s easier to cut.
Once cut, use a spoon to scoop out the seeds and stringy fibers from the middle.
Place each half cut side down and slice into in half again, again going through the stem. You should now have four quarters.
Now cut each one of these quarters in half again, so you have eight large wedges.
Turn each wedge face up.
Starting with one point of the wedge, slice it into thirds or fourths, depending on your preferred size and the size of your kabocha.
Place wedges on a wire rack on a baking sheet and roast for 40-45 minutes, until you start to see some dark brown areas at the tips of some of the kabocha wedges.
Take out the tray and let cool (if you want). Wedges can be reheated for 5-10 minutes in a 400 ºF degree oven if you prefer them warm, stored in the refrigerator, or frozen. If you freeze them, I suggest freezing on a baking sheet prior to storing in a bag, since they otherwise tend to stick.