Collect all your ingredients: Mount Cook Alpine King Salmon, saké, miso paste, coconut sugar, sushi rice, purple broccolini, pickled red onions, avocado, scallions, and salmon roe. Ensure you also have tools like a saucepan, whisk, bowl, parchment paper, baking sheet, and a broiler-ready oven.
In a medium-sized saucepan, pour 1/2 cup of saké and bring it to a gentle simmer over medium heat. Stir in 1/4 cup of miso paste and whisk until fully dissolved. Gradually add 2 tablespoons of coconut sugar, whisking continuously. Keep stirring as the mixture thickens and reduces by half, ensuring the sauce does not stick or burn. This process should take about 10 minutes. Once reduced, remove from heat and let it cool completely before using.
Transfer the hot marinade into a shallow bowl and place it in the refrigerator for about 10-15 minutes to cool quickly. This step is important to avoid cooking the salmon prematurely when applying the marinade.
While the marinade cools, rinse the sushi-grade Mount Cook Alpine King Salmon filets under cold water and pat them dry with paper towels. Check for any remaining pin bones by gently running your fingers over the flesh and remove them with tweezers if needed.
Once the marinade has cooled, place the salmon filets into a shallow dish. Pour the miso marinade over the salmon, making sure to coat all sides evenly. Use your hands or a brush to gently massage the marinade into the filets. Cover the dish with plastic wrap and refrigerate for 48 hours, turning the filets once halfway through the marination process.
Remove the salmon from the fridge and gently scrape off any excess marinade using the back of a spoon or your fingers. Be careful not to remove all the marinade, just the excess that might burn. Place the salmon filets on the prepared baking sheet and brush a fresh, thin layer of the reserved marinade over the top.
Slide the baking sheet under the preheated broiler. Broil the salmon for about 5 minutes, keeping a close eye on the color. You’re looking for a deep golden-brown caramelization on the edges. Rotate the pan halfway through for even cooking. Use a meat thermometer to check the internal temperature, aiming for around 130°F for medium-rare.
Remove the salmon from the oven and let it rest on the baking sheet for 3-5 minutes. The residual heat will continue to cook the salmon slightly, bringing it up to around 150°F.
Begin plating by spreading a layer of sushi rice across the bottom of your bowl. Arrange the broiled salmon filets on top of the rice, then place the blanched broccolini and pickled red onions on either side. Add the sliced avocado next to the salmon.
For the final touch, add a generous spoonful of salmon roe over the salmon and sprinkle the chopped scallions on top for brightness and a pop of color.
Serve the broiled miso salmon bowl immediately, appreciating the rich umami flavors, caramelized miso crust, and contrasting textures of the rice, vegetables, and roe. Take a moment to enjoy the mindful ritual of the dish's preparation.