Preheat the oven to 400˚F. Heat the olive oil in a small skillet over moderate heat. Add the chorizo and brown on all sides, about 3 minutes. Transfer the skillet to the oven and roast until the sausages feel firm, about 5 minutes. Set aside to cool slightly, then cut into 1-inch-thick slices.
Put the potatoes in a saucepan with salted water to cover by 1 inch. Bring to a boil, adjust the heat to maintain a simmer, and cook until the potatoes are tender when pierced, about 15 minutes. Drain and let cool. Peel, then cut into 1-inch chunks.
Make the tomato broth: Heat the olive oil in a large pot over high heat. Add the bell peppers and saute, stirring, for about 3 minutes to soften them, then add the garlic and chile flakes. Lower the heat and cook for about 1 minute to release the garlic fragrance, then add the tomatoes and the oregano, rubbing the herb between your fingers. Simmer briskly until the tomatoes soften, about 2 minutes, then add the stock and wine. Simmer for about 5 minutes to thicken the liquid slightly, then add the chorizo and potatoes. Simmer for 5 minutes to develop the flavor. Taste and adjust the seasoning.
Season the fish on both sides with salt and pepper. Arrange the fillets on top of the stew, then cover and simmer gently until the fish is fully cooked, about 10 minutes. Divide the chorizo, potatoes, and broth among 4 soup bowls, then top each portion with a fish fillet. Serve immediately.
Enjoy with a glass of Cakebread Cellars Pinot Noir.