Wrap garlic in foil and bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 30 minutes until soft. Wash, peel and quarter the potatoes. Cook in boiling salted water for about 15 minutes until soft
In the meantime, cut the chorizo into slices about 5 mm thick. Peel the onion and cut into narrow slices. Wash and halve the tomatoes. Heat olive oil in a pan and fry the onion until transparent. Add chorizo and fry. Fry the tomatoes about 2 minutes before the end of the cooking time. Keep warm
Squeeze the garlic out of its skin, put it in a pot with milk and heat it up, melt butter in it. Drain the potatoes, add them to the milk mixture and mash them with a potato masher to make puree. Season with salt and keep warm
Wash the fish, dab dry, season with salt and pepper and turn lightly in flour. Heat oil in a pan and fry fish for 2-3 minutes on each side. Divide the mashed potatoes on plates, arrange the fish on top and pour on the onion, chorizo and tomatoes