Yellowtail Poke with Glass Noodles and Pear

Name: Yellowtail Poke with Glass Noodles and Pear
Ingredients: 4 ounces thin bean thread noodles; 1/4 cup dried arame (seaweed); 3 tablespoons unseasoned rice vinegar; 3 tablespoons white soy sauce; 2 tablespoons mirin; 2 teaspoons fresh lemon juice; 1 1/2 teaspoons finely grated green chile (such as serrano); 1 teaspoon toasted sesame oil; 1 firm green pear, cut into matchsticks; 1/2 small sweet onion, cut lengthwise into quarters, thinly sliced crosswise; 12 ounces yellowtail, cut into 1/2-inch pieces; 1/2 cup torn mint leaves; 2 tablespoons finely chopped chives; 2 teaspoons toasted white and/or black sesame seeds, plus more for serving; Kosher salt; Gochugaru (coarse Korean hot pepper powder) or crushed red pepper flakes (for serving)