Seared Tuna with Asparagus and Limey Noodles

Name: Seared Tuna with Asparagus and Limey Noodles
Ingredients: 2 tablespoons soy sauce; 2 tablespoons lime juice; 1 tablespoon water; 2 teaspoons sesame oil; Pinch red chile flake; 4 oz udon noodles, cooked according to package directions, drained and cooled slightly under running cold water; Two 4 oz tuna steaks; Salt for sprinkling; Freshly ground black pepper; 1/3 cup sesame seeds, white, black or mixed; 1 tablespoon vegetable oil; 12 stalks asparagus, trimmed and cut into 1-inch pieces; 2 green onions; 2 tablespoons minced cilantro plus more for garnish; Pickled ginger as an accompaniment