Soba Bukkake with Chashu Pork and Sesame Vinaigrette
Make the mentsuyu Stir together 4 cups water, bonito flakes, soy sauce, mirin, brown sugar, and shiitake in a medium saucepan over medium-low, and slowly bring to a simmer. Simmer until flavors meld, about 5 minutes. Remove from heat, and add kombu. Let stand 10 minutes. Pour mixture through a fine wire-mesh strainer into a