Stir the miso with the tamari, sesame oil and grated ginger into a thick paste. Brush the top of the salmon fillet generously with it and let it stand for fifteen minutes. Miso is fermented and packed with umami; because of the salt, it also draws some moisture out of the fish, which helps the glaze adhere better.
Cook the brown rice in plenty of salted water for about twenty-five minutes until al dente, then drain.
Preheat the oven grill. Place the salmon on a baking sheet lined with parchment paper and place it under the grill for eight to ten minutes, until the glaze is dark and glossy and the fish is just translucent in the center. Keep a close eye on it during the last few minutes, as miso contains sugars from fermentation and can burn quickly.
Meanwhile, heat the olive oil in a wok, fry the garlic slices for half a minute and add the broccolini with a splash of water. Stir-fry for three to four minutes with the lid on until the stems are al dente and the florets are bright green. Serve the salmon on the rice with the broccolini on the side, sprinkle with sesame seeds and squeeze lime juice over it.