In a small bowl, mix the miso with 1 tablespoon of hot water to loosen. Stir in the mustard and maple syrup until uniform. Taste and add a little more maple if you want a sweeter sauce. You can also add a bit of water to thin it out if needed.

In a small skillet over medium-low heat, toast the sesame seeds until golden, about 3 minutes. Transfer the seeds to a small dish so they don’t burn.

Pat the scallops dry and set on a tray or plate.

Add enough olive oil to coat a large cast-iron skillet and set it over medium-high heat. Add two-thirds of the snap peas (ideally the larger ones) and sear, undisturbed, until browned and softened, about 3 minutes. Flip and cook for another minute, just to soften, then transfer the peas to a large dish.

In the same pan, add a drizzle of oil and swirl to coat. Add half of the scallops, evenly spacing them out, then immediately add half of the butter and drag it around the scallops as it foams. Don’t move the scallops as they cook. After 4 minutes, once they are caramelized and golden, turn the scallops. Repeatedly baste the scallops with the hot fat for another minute, then transfer them to the dish with the cooked peas. Repeat with the remainder of the scallops, adding in more oil and the last of the butter as you did the first batch.

Swirl some miso mustard onto each of two plates, bringing the remainder to the table to add more if needed. Divide the cooked snap peas between the plates, then add all but 6 of the uncooked peas. Nestle in the scallops, slice the remaining 6 snap peas in half lengthwise to arrange as garnish, and shower with sesame seeds.