Heat a medium to large skillet over medium heat. Add the chorizo after you take it out of the casing.
Break up the chorizo so it resembles ground beef. Add the onion and cook for about 5 minutes.
Peel, rinse and chop the russet potato into small cubes.
Set chorizo aside in a bowl (dab some grease off with paper towel) and using the leftover grease, cook the potatoes covered for 10 minutes or until the potatoes start to become soft. Add 1/2 tsp salt to potatoes.
Add the chorizo back into the skillet/pan with the potatoes and cook for an additional 5 minutes.
Meanwhile, in a large bowl, whisk the eggs and the milk together.
Cook the scrambled eggs in a separate non-stick pan/skillet. I did not add any salt to eggs since the chorizo/potato mixture has plenty of flavor.
Heat the flour tortillas using your desired method, I do it over an open flame, and start the burrito assembly.
Cut medium pieces of parchment paper and place warm tortilla on top. Add scrambled eggs and chorizo-potato mixture. Fold burrito and then the parchment paper the same way. Finally, cover with a layer of aluminum foil. Place them in freezer and when you are ready to eat, take aluminum foil off before microwaving.
Microwave frozen burritos for 2 1/2-3 minutes. If serving right away, garnish with cilantro and salsa!