De-seed the piments and peppers and cut them into strips. Then soften them in the oil in a large casserole. Add the onions, garlic and fish and cook together for 5 minutes.
Bring the wine to the boil, add it and the tomatoes to the pot – the wine should cover the contents. Season and sprinkle with the thyme leaves.
Bring back to the boil and add the potatoes. Simmer gentl