Use an ice cream scoop to scoop the risotto into 1 to 1½~inch balls. Set aside on a parchment-lined half sheet pan. (You can refrigerate or quick~freeze the risotto balls at this point.)
Place the egg whites in one pie plate. Combine the panko crumbs, salt and pepper in another pie plate.
Dip the risotto bites first into the egg wash and then into the panko bread crumbs, coating all sides. Shake off excess panko. Place back on the half sheet.
Dip your finger in water and press into the top of the risotto balls to make more of a disk. (At this point, you can refrigerate or freeze the pumpkin risotto bites.
In a large skillet, add oil to a depth of 1/2 inch. Heat the oil over medium~high heat until it reaches 375˚F.
Fry the risotto bites, 3 to 4 at a time, until golden brown on both sides, about 2 minutes per side. Remove with a metal spatula. Drain on a sheet pan lined with paper towels. (After frying, you can keep them warm in a 200˚F. oven until time to garnish and serve.)
Le the risotto bites cool. Top each with 1 teaspoon crème fraîche and a green onion slice. serve immediately.