Step 1Combine the chicken broth, mirin, sake, soy sauce, sugar and ginger in a medium, heavy-bottom saucepan and bring to a boil, stirring occasionally.
Step 2Reduce the heat to simmer and cook until the sauce is reduced to 1 cup. Remove from heat and reserve.
Step 1Fill a large, heavy-bottom saucepan with enough oil to come 3 inches up the side. Heat the oil until a thermometer inserted reads 350 degrees.
Step 2Season the wings with the salt and pepper, then dredge with the cornstarch. Fry the wings, a few at a time, until lightly golden and cooked through, about 8 minutes. Drain the wings on a rack.
Step 3When all the wings are fried, heat a wok or heavy saute pan over high heat. Add the reserved ginger-soy sauce and bring to a boil, then add the wings, stirring to coat. Cook the wings in the sauce, stirring constantly, until the sauce reduces enough that it coats the wings in a thick, syrupy glaze.
Step 4Remove from the heat and toss the wings with the sesame seeds. Serve immediately.