Heat a medium skillet over medium high heat. Add extra-virgin olive oil, 2 turns of the pan, and the chorizo. Cook sausage 2 minutes, flip cook another minute then add potatoes and onions to the pan in an even layer over the sausage. Season the potatoes and onions with salt, pepper and paprika then turn sections of the potatoes using a spatula so that the chorizo is on top and potatoes and onions are on the bottom. Place a smaller skillet on top and press down. Weight the skillet with a few heavy cans. Cook 10 to 12 minutes. Remove weight and turn again to combine all ingredients. Cook another 3 to 4 minutes then add parsley, remove from heat and serve.