Bring 3/4 cup water, stock concentrate, and soy sauce to a boil in a small pot. Once boiling, add rice. Cover, lower heat, and reduce to a simmer. Cook until tender, 15-20 minutes. Remove from heat and keep covered.

Wash and dry all produce. Cut off and discard root ends of bok choy, then separate into individual stalks. Thinly slice scallions, keeping greens and whites separate. Halve lime. Cut one half into wedges. Peel, then finely grate ginger. Grate garlic.

In a small bowl, combine mayonnaise, a squeeze of lime juice, a pinch of garlic, a pinch of ginger, and wasabi paste (to taste—start with a pinch and add more from there). Add just enough water to give dressing a drizzly consistency, 2-3 tsp. Season with salt and pepper.

Heat a drizzle of oil in a large pan over medium heat. Add scallion whites, remaining garlic, and remaining ginger. Cook, tossing, until slightly softened, 1-2 minutes. Add bok choy and 1 TBSP water. Cook, tossing, until leaves wilt, 2-3 minutes. Season with salt and pepper. Remove mixture from pan and set aside, covering with aluminum foil to keep warm.

Heat a drizzle of oil in same pan over medium-high heat. Season salmon all over with salt and pepper. Add to pan skin-side down. Cook until skin is crisp and browned, 5-6 minutes. Lower heat to medium and flip salmon. Cook until opaque throughout, another 3-4 minutes.

Divide rice between plates. Top with bok choy and salmon. Drizzle with dressing and garnish with scallion greens. Serve with lime wedges on the side for squeezing.