This dish looks really beautiful, I think, because of the contrast of the bright orange sauce poured over the white cauliflower and grain 😀
I just boiled one smaller cauliflower head split into two halves (it needs about 10-15 minutes, submerged in salted water). For the sauce I cooked hokkaido pumpkin cut into chunks, and again, just enough water to submerge. You can cook this a bit longer than the cauliflower, together with grated brown rice mochi (for creamy texture), barley (or other) miso to taste, and a dash of lemon juice. Then blend until smooth and bring back to boil for a second.
I also blanched the cauliflower leaves, since they looked nice (and again – here´s your fiber!) and served the meal with rice and barley mix.