Heat 1 tablespoon of the oil in a large skillet over medium-high heat. Season the shrimp with ½ teaspoon salt and ¼ teaspoon pepper and cook, tossing occasionally, until opaque throughout, 4 to 6 minutes.
Meanwhile, whisk together the miso, vinegar, the remaining tablespoon of oil, and 3 tablespoons water in a small bowl.
Toss the greens, snow peas, radishes, carrots, and scallions in a large bowl. Top with the shrimp and drizzle with the dressing.