Sprinkle the beef liberally with salt, allow to sit at room temperature while you prepare the sauce.
Preheat a grill to medium-high.
In a saucepan whisk together the cornstarch, ginger, garlic, soy sauce, beer, brown sugar, sesame oil and black pepper. Bring to a boil. Allow to boil, stirring frequently, until thickened, about 5 minutes.
Thread the beef cubes onto grill skewers. Brush liberally with sauce.
Add the skewers to the grill. Turn every 2-3 minutes, brushing with glaze every time you turn.
Cook until steak has grill marks and is firm to the touch, about 6-8 minutes.
Add to a serving plate, sprinkle with green onions.