Place mashed potatoes and onions in a large mixing bowl. In a small bowl beat the egg yolks and add to the potatoes.

Add the flour, milk, and salt and pepper. Mix until well combined and smooth. Cover bowl with plastic wrap and place in the refrigerator for about 30 minutes.

Scoop out about a ¼ cup of the potato mixture and form into a ball, flatten ball into a patty and place on a parchment or wax paper lined baking sheet. Place baking sheet in the fridge for about 20 minutes to firm up for breading.

Set up a breading station with three small bowls. Put about a ¼ cup of cornstarch in the first, the beaten egg in the second, and the bread crumbs in the third.

Working with the chilled potatoes one at a time, dust a potato cake with the corn starch, dredge in the beaten egg, roll to coat with bread crumbs and then return to the baking sheet. Once all cakes are breaded, return to the fridge to firm up before frying.

Pour about ½ inch of oil in the bottom of a large skillet. Heat oil to 170°F – 180°F or until it shimmers. You can also test the oil by flicking a bit of flour. If the flour sizzles the oil is ready.

Carefully slide a few of the cakes at a time into the oil. Cook for about 3 – 4 minutes or until you see a golden color starting to form, carefully turn the cakes and fry for about the same amount of time.

Remove from the oil and place on a wire rack over a sheet pan to drain.

Delicious served with an Aioli as an appetizer.