1⁄2 cup sesame oil
1⁄4 cup mirin
2 tbsp. white miso
1 lb. peeled and deveined tail-on shrimp (about 24)
1 (8-oz.) package soba noodles
6 oz. watercress
4 scallions, cut into 1 1⁄2" pieces
2 tbsp. toasted seeds
Whisk oil, mirin, and miso in a bowl. Toss shrimp with half, cover, and refrigerate at least 30 minutes; reserve remaining marinade to dress your salad.
Bring a medium pot of water to a boil; cook soba, stirring occasionally, 6-8 minutes. Drain and run under cold water to cool. Toss with remaining marinade, watercress, and scallions.
Meanwhile, build a medium-hot fire in a charcoal grill, or heat a gas grill to medium. (Alternatively, heat a cast-iron grill pan over medium-high heat.) Thread shrimp onto skewers; grill, turning once, until cooked through, about 3 minutes. Serve with soba salad and toasted seeds.