For the panna cotta, bring milk, salt, coriander, fennel seed, zest, and kombu to 165 degrees over low heat in a small non-reactive sauce pot and allow the base to steep for 15 minutes. Carefully strain and reserve the milk. Bloom the gelatin in cool water. While the gelatin hydrates, finish the base in a non-reactive sauce pan over medium heat by adding the white shoyu and reducing until dry. Deglaze the pan with the yuzu and lemon juices, then add reserved milk. Squeeze the excess water out of the gelatin by wringing it gently in your hands, then add to the base. Warm to 150 degrees while gently stirring. Once warmed for 2 minutes, add the cream and stir for an additional 30 seconds. Ladle the panna cotta into spoons or small ramekins and refrigerate to set for a minimum of 2 hours before serving.
Blanch the scallions and chives in salted boiling water for 10 seconds, then plunge into an ice bath to arrest cooking. Combine blanched scallions and chives with grapeseed oil and salt and purée for 30 seconds. Strain through cheese cloth and reserve under refrigeration for up to two days.
For the puffed forbidden rice, simmer the rice in a small pot of water over low heat until the grains are completely cooked through. Strain the rice and discard any remaining liquid. Dehydrate the rice on a Silpat lined baking sheet (or silicone baking mat) in a low oven or food dehydrator at 140 degrees for 2-3 hours. Dry until sheet pulls away from the Silpat. When dry enough to tear, portion the rice into 2-inch strips. Heat the oil in a fryer or small sauce pan with high sides to 375 degrees. Fry the rice in batches, drain on paper towels and season with sea salt. Rice may be prepared the day prior.
To plate, remove the spoons of panna cotta from the refrigerator. Place a third of an ounce of caviar onto the spoons and garnish with scallion oil, puffed forbidden rice, toasted kombu and benne seeds.