Light a grill or preheat a grill pan. In a bowl, toss the sirloin, mushrooms and scallions with the canola oil and season with salt. Thread the meat and vegetables onto 8 skewers.
In a bowl, combine the brown sugar with the soy sauce, miso paste and sesame oil. Grill the skewers over high heat, turning, until the meat is nearly cooked, about 2 minutes. Brush the skewers with the glaze and grill until they are lightly charred and cooked through, 2 to 3 minutes longer. Transfer the yakitori to plates, sprinkle with the sesame seeds and serve.
Sake: Fruity, earthy, mushroom-scented Ama No To Heaven's Door Tokubetsu Junmai.
Pairing by Rick Smith and Hiroko Furukawa of New York City's East Village sake shop Sakaya (sakayanyc.com).