Peel the potatoes and rinse with water then cook it in a large pot cover with water. Let it boil on low heat until the potatoes completely cooked.
Press the cooked potatoes using metal sieve then place the puree in a saucepan and cook over medium heat for 1-2 minutes. Stir continuously. Add in 2 egg yolks, corn flour and salt & pepper and nutmeg to taste. Remove the paste from heat when it becomes elastic paste. Set aside.
Cook vinegar, shallot and tarragon in a saucepan over medium heat. Lower the heat and add in 3 eggs yolks. Mix well using a wire whisk. Add in a little of cold water, continue to whisk until a thick foam is observed. Remove from heat and set aside.
Heat MERRIS cooking oil in a wok on medium heat. Fill the potato paste into a plastic bag with star nozzle. When the oil is hot, pipe the potato paste directly into the oil to form churros. Fried the churros for 5 minutes until golden brown and crispy.