Prepare mackerel in a convenient way for you. Boil, bake in the oven or microwave.
You can also take hot smoked mackerel.
I baked in the oven in foil, seasoning the fish with salt, pepper and lemon juice, 20-25 minutes at a temperature of 180 degrees.
Boil the potatoes until tender.
While the fish is baking and the potatoes are cooking, wash the celery, if necessary remove the top hard layer and cut thinly across.
Wash the onion and finely chop it.
Prepare the dressing. Mix the yogurt, mustard, olive oil and soy sauce. I used light soy sauce.
The finished mackerel is cleaned from the bones and disassembled into not too small pieces.
Cool the boiled potatoes slightly and cut them into cubes. Mix the sliced potatoes immediately with the dressing, add the fish, onion and celery. Stir and serve warm.