Wash the pollock fillet, dab dry and cut into large cubes. Sprinkle with lemon juice and put aside. Peel onion and garlic. Chop onion coarsely, chop garlic. Peel, wash and coarsely dice the potatoes.
Drain the fish. Mix flour and some salt, turn the fish in it. Heat 2 tablespoons of oil in a frying pan, fry the fish for 2-3 minutes while turning and remove.
Put 2 tablespoons of oil and potatoes into the hot pan and fry for about 5 minutes, turning. Finally add onion and garlic, fry briefly, season with salt and cayenne pepper. Add tomatoes and stock.
Mash tomatoes with a spatula, bring to the boil and braise over medium heat for about 5 minutes.
Drain the corn and bean mix. Wash the coriander, shake dry and chop coarsely. When the potatoes are soft, add the corn and bean mix and half of the coriander and bring to the boil briefly. Season to taste with salt and cayenne pepper.
Carefully fold in the fish and warm it up for 1-2 minutes. Sprinkle with remaining coriander.