Combine the miso paste, brown sugar, soy sauce, rice vinegar, half the ginger, and half the garlic in a bowl. Whisk until smooth, adding a splash of warm water if it’s too thick. This glaze infuses the salmon with deep, savory notes that mimic the restaurant’s signature taste.

Place the salmon fillets in a shallow dish and coat them evenly with half the glaze, reserving the rest for basting. Cover and refrigerate for 30 minutes to an hour to let the flavors penetrate. This step tenderizes the fish and builds that caramelized crust during cooking.

Melt 2 tablespoons of butter in a small saucepan over medium heat, then add the shallot, remaining ginger, and garlic, sautéing until softened, about 2 minutes. Pour in the sake and simmer for 5 minutes to reduce, then whisk in the remaining butter until emulsified and glossy. Set aside to keep warm, creating a rich sauce that elevates the dish.

Bring a medium pot of salted water to a boil, add the snow peas, and cook for 2 minutes until bright green and crisp-tender. Drain and immediately plunge into ice water to stop cooking, then pat dry. This preserves their vibrant color and crunch, adding a fresh contrast to the salmon.

Preheat the oven to 375°F and line a baking sheet with foil lightly brushed with oil. Place the marinated salmon on the sheet and bake for 12-15 minutes, basting with reserved glaze halfway through, until the fish flakes easily but remains moist. For extra caramelization, broil for the last 1-2 minutes, watching closely to avoid burning.

Arrange the cooked salmon over a bed of jasmine rice if using, with snow peas alongside. Drizzle generously with the sake butter sauce and sprinkle with sliced green onions. This final assembly brings all elements together for a visually appealing and flavorful plate.