Peel and grate potatoes and place in medium bowl. 

Finely chop onion and add to bowl. Add egg, salt, pepper and flour and mix to combine. 

Heat frying pan over medium high heat.  Add enough oil for frying, about 1-inch deep.

Once oil is hot spoon potato mixture by the tablespoon into pan.  Fry until golden, flip and fry the other side. Remove to a paper towel-lined tray, serve with sour cream.