Mushrooms ( I have frozen, not pre-thawed) put fry in olive oil, add a little salt and pepper. In another pan fry the carrots and onions. Carrots three on a coarse grater, onion finely shinkuem. Eggs boil.

Cheese grate on a fine grater. With canned drain off the excess liquid and with a fork mash the fish. Eggs cut into cubes.

Salad spread layers, lubricating each layer of mayonnaise. So, first layer the mushrooms, then the fish. Next the carrots, onion, eggs and complete the salad with a layer of cheese.