Boil the potato in salted hot water until fork tender, approximately 30 minutes. Allow them to cool and then mash them or use a potato ricer to create a smooth puree. You should have approximately 1 cup of mashed potatoes.

Add the evaporated milk, egg yolk, flour and salt to the potato. Combine well and set aside.

Remove casing from the chorizo. In a medium saute pan, render the fat from the sausage on low heat. After a few minutes turn the heat up to medium and brown the sausage while breaking it apart with a spatula. Allow the bottom of the pan to brown and then deglaze it periodically with 1-2 tablespoons of water. When the pan sizzles, use the spatula to scrape up the brown bits and incorporate them with the chorizo; the water will cook away. Continue to break apart the chorizo so you have very small pieces. Once the sausage bits are brown and crunchy (15-20 minutes), remove from the pan and allow excess fat to drain on a paper towel. Measure out 1/2 cup of chorizo and set aside.

In the same saute pan, sweat the onions and garlic on medium-low heat. If there's no leftover fat from the chorizo, add 1-2 teaspoons of olive oil to the pan to prevent sticking. Saute for a few minutes and then turn off the heat when the onions and garlic are just starting to brown. Set aside.

Toast the pine nuts in a 350 degree F oven until golden brown, approximately 5 minutes.

Heat up the vegetable oil to 360 degrees F in a deep fryer or medium sauce pot.

Place breadcrumbs in a bowl.

Combine the potato mixture, chorizo, pine nuts and Manchego cheese. Measure out 2 tablespoons of the mixture and use your hands to form a ball. Roll it around in the breadcrumbs and set aside. Repeat with the rest of the mixture.

Fry the croquettes until golden brown, approximately 5 minutes.

Carefully remove them from the oil with a slotted spoon and allow the excess oil to drain on paper towels for a minute or two.

Serve hot or at room temperature.