Heat 1 tbsp. of oil in a large sauté pan at medium-low heat. Add onions and cook until soft and translucent, about 10 min. It’s ok if they brown a little bit.
While the onions are cooking, place your cut potatoes in a small saucepot with salted water. Bring the water up to a simmer at high heat. Lower heat to medium and let the potatoes cook for 5 minutes.
Drain the potatoes and add them to the pan with the onion. Turn heat up to medium-high. Cook potatoes and onions for 5 minutes or until the potatoes begin to brown. Add more oil if necessary.
Add cooked chorizo to the pan and mix well. Cook for one more minute.
Season with salt and pepper.
Serve with warm tortillas and the salsa of your choice.