In a separate bowl, whisk together the vegan eggs (made per package instructions), milk, and black pepper until combined. Then add them to the hashbrown mixture and stir to combine. Pour the mixture into a 9×9-inch baking dish, and top with the remaining 1/2 cup of shredded cheese. Cover with aluminum foil and bake for 20 minutes. Then remove the aluminum foil and bake for an additional 10-15 minutes until the top of the potatoes begin to lightly brown. Remove and let the casserole rest for 5 minutes. Sprinkle with green onions and serve!