The necessary ingredients.

Fish cut into small pieces, dip them in flour and fry in vegetable oil until Golden brown (I think to reduce the calorie content you can skip this step). And then spread on a greased baking sheet.

Sprinkle with corn. On top of the onion rings. Sprinkle with lemon juice.

To grease with mayonnaise (you can substitute sour cream with salt, seasoning or a mixture of sour cream+mayonnaise). Sprinkle with cheese and into the oven until Golden top. I put on 220 C for 30 minutes. But in my experience that other oven bake faster. Most likely can be shortened to 10 minutes at the same temperature. The result is something like a casserole. Bon appetit!