Prepare the meat. Preheat oven to 350°F. Place cubed meat in a baking pan with the water, soy sauce, and sugar. Cover well and bake for 3-3 1/2 hours or until meat is soft.
Remove meat from oven. Mix half the liquid from the pan with sweet glaze ingredients. Discard remaining liquid. Place sweet glaze into a large skillet with the meat. Cook until glaze thickens. If glaze isn’t thickening, you can add a little tomato paste or some cornstarch slurry (½ tsp cornstarch to 1-2 tbsp of cold water) to thicken it. Coat meat in glaze.
Prepare the tempura rice. Cook sushi rice according to package directions. Meanwhile, in another saucepan, combine rice vinegar and sugar. Cook until thickened and syrupy. Mix into cooked sushi rice, and spread on a baking sheet to cool.
Once rice is cool, form into 3-inch circles about ½-inch thick. They should resemble small hockey pucks. To form the pucks you’ll want to wet your hands and keep a bowl of water next to you so you could keep on dipping your hands. Pat the rice very well. (Editor's note: At this point I froze the rice patties for 10 minutes so they would retain their shape during the frying process, although the chef does not.)
Heat oil in a saucepan or deep fryer. Mix tempura mixture according to package directions (or make your own, see **note). Coat rice patties in mix and fry for 3-4 minutes.
To serve, top each tempura rice cake with 5-6 pieces of meat. Garnish with petite greens and some roasted sesame seeds.