Step 1Start by assembling the honey-miso sauce: Peel 2" piece ginger with a spoon. (We find that a spoon is better for navigating the bumpy exterior of a knob of ginger than a vegetable peeler, but you do you.) Finely grate ginger with a Microplane into a small bowl.Step 2Add 2 Tbsp. miso, 1 Tbsp. oil, 1 Tbsp. vinegar, 1 Tbsp. honey, and 1 Tbsp. water to the bowl with with the ginger. Whisk to combine and set aside. This is a great all-purpose sauce, so making extra wouldn't hurt! Use it to top grain bowls, roasted vegetables, or any other simply-cooked protein.Step 3Heat a small skillet over medium. Toast 1 Tbsp. sesame seeds, tossing frequently, until seeds are a light golden color and slightly fragrant, about 2 minutes. Seeds you toast yourself are always going to be more flavorful than the ones you buy already toasted, but we won't judge if you don't feel like going the extra mile.Step 4Trim the root ends from 3 scallions and thinly slice crosswise.Step 5Lightly season the flesh of 4 salmon fillets on all sides with salt. Place pieces skin side down in a cold—as in not preheated; you don't have to refrigerate it or anything—cast-iron skillet. (This might seem a little weird, but trust us—the skin will render nicely and get way more crispy this way.) Heat skillet over medium and let the salmon cook undisturbed for 5 minutes.Step 6Press down lightly on flesh with a spatula to ensure all parts of the skin are making contact with the pan. At this point it should be opaque at least halfway up the flesh side. Continue to cook skin side down until fish is mostly opaque and skin is crispy, about 5 minutes longer. If the skin is still sticking to the pan at this point, don't try to un-stick it—you'll know that it's ready to flip when it releases on its own.Step 7Using a fish spatula, gently flip the fillets, then remove the pan from the heat. Continue to cook off-heat (the pan will still be plenty hot) until flesh is juuuuuuuust cooked through, about 1 minute longer for regular-sized fillets, but very thick ones might take up to 3 minutes more—you can use a fork to flake the fish slightly to check for doneness; you're looking for the inside to be still a little pink and translucent.Step 8Spoon miso-honey sauce onto a platter. Place salmon fillets skin side up on top of the sauce. Sprinkle with toasted sesame seeds and scallions. Et voila! Dinner is served.