STEP 3
Whisk soy sauce, maple syrup, miso, vinegar, and 1⁄4 tsp. red pepper flakes in a small bowl to combine. Set glaze aside.
STEP 4
Heat oil in a medium nonstick skillet over medium. Season salmon with salt and place in skillet skin side down. Cook, shaking pan occasionally to redistribute oil in skillet, until skin is very crisp and deep golden brown, 7–9 minutes. Turn salmon and continue to cook just until very lightly browned on flesh side (by this point it should be nearly cooked through), about 2 minutes longer. Using a spatula to hold fish in place, pour off fat from skillet. (Or transfer salmon to a plate while you do this and return fish to skillet before proceeding.) Reduce heat to low and add reserved glaze. Cook, stirring occasionally, until glaze begins to thicken, about 1 minute. Baste salmon with glaze and cook, basting occasionally, until glaze evenly coats fish, about 1 minute.
STEP 5
Divide rice among plates and arrange fish on top. Drizzle with any leftover glaze. Scatter scallions, sesame seeds, and red pepper flakes over. Serve with lime wedges for squeezing over.