¾ pound fresh Mexican chorizo sausage, casing removed
vegetable oil, as needed
1 small onion, diced
salt and ground black pepper to taste
Place potatoes into a large pot and cover with salted water; bring to a boil. Reduce heat to medium-low and simmer until slightly soft, 5 to 6 minutes. Drain. Meanwhile, cook chorizo over medium-high heat in a large skillet, breaking up any large clumps, until browned, 5 to 6 minutes. Remove chorizo to a paper towel-lined plate using a slotted spoon, reserving about 1 tablespoon of grease in the skillet. Add oil if necessary to make up 1 tablespoon. Cook onion in the same skillet over medium heat, stirring occasionally, until they begin to soften and brown, 4 to 5 minutes. Add potatoes to the skillet and saute until potatoes are lightly browned, 5 to 7 minutes. Stir in chorizo and season with salt and pepper.