Chop the onion, and place the yolk and whites into separate bowls.
Peel the potato, and grate on the large holes of a box grater.
Remove as much of the moisture from the potatoes as possible.
Chef’s Tip: I accomplish this by placing them into a tea towel, and twisting and squeezing the towel until I’ve removed most of the water.
Combine the egg white, the potato, and chopped onion in a bowl, season with salt and pepper, and toss to combine.
Using a 3.5-inch salad ring place 2 ounces of the hash browns into the ring and press down.
Place the breakfast sausage on top of hash browns, and press down.
Place two more ounces of the hash browns on top of the sausage, and firmly press together.
Heat the oil in a skillet over medium heat.
Carefully place the hash browns (ring and all) into the skillet.
Allow to cook for about 5 minutes, or until the bottom is crispy.
Carefully flip the hash brown ring and cook another 5 minutes.
Chef’s Tip: The trick here is to get the temperature of the pan hot enough to crisp the potatoes and cook the sausage without burning the potatoes. Medium heat on most stoves is about right.
Chef’s Note: Do you have to use a cooking ring… Nah, you can just press everything together with a spatula. But it looks SO good when you use a ring. As a matter of fact, the ones that I use are called: Crumpet rings.
When the hash browns and sausage are almost finished, take a small saucepan and boil about a cup of water.
After it boils, take off the heat, and add the egg yolk, being very careful not to break it.
Leave it in the hot water for about 3 minutes.
Chef’s Note: You want it cooked, but still nice and runny.
Plate the hash browns and sausage patty on a nice plain plate, and place the egg yolk on top... don't break the yolk.
Add some chopped fresh rosemary, and a bit of black pepper for garnish. Serve immediately.
To eat, break the yolk over the hash browns, and let it seep into the hash browns. Enjoy.