Mix the potatoes, onions, flour, salt, pepper, and eggs thoroughly in a bowl. Melt clarified butter on a pre-heated non-stick skillet at medium-high heat.
Drop spoonfuls of the potato batter onto the skillet, leaving space between each cake. Carefully flip cakes when edges appear brown, about two minutes. Cook for one additional minute and then remove from skillet. Continue to cook batches in same manner, adding more clarified butter as needed. Place cakes on paper towel to remove any excess butter.
Top with a dollop of crème fraiche and a teaspoon of caviar of your choice and serve.