How to Make It
In a large pot, brown the chorizo over medium-high heat, 1 to 2 minutes.
Add the leeks and cook, stirring occasionally, until beginning to soften, 3 to 4 minutes.
Add the potatoes, tomatoes (with their juices), 3 cups water, ¾ teaspoon salt, and ¼ teaspoon pepper. Cover and bring to a boil.
Reduce heat and simmer until the potatoes are just tender, 10 to 12 minutes.
Add the fish and simmer gently until opaque throughout, 5 to 6 minutes. Stir in the parsley before serving.