In a large pot, heat the olive oil over medium heat. Add the diced onion and cook until translucent, about 5 minutes.
Stir in the minced garlic and sliced chorizo, cooking for another 3-4 minutes until the chorizo is browned and fragrant.
Add the diced potatoes, diced tomatoes (with their juices), chicken broth, smoked paprika, and dried oregano. Stir to combine.
Bring the mixture to a boil, then reduce the heat to low. Cover and let simmer for about 25-30 minutes, or until the potatoes are tender.
Season with salt and pepper to taste. Serve hot, garnished with fresh parsley.