Clean fish, simmer in salted water for 7 minutes.
Remove fish, skin and flake flesh.
Place tomatoes in boiling water until skin loosens, then remove the skin.
Place tomatoes and the fish in an ovenproof dish.
Blend the flour with a little milk, when blended and smooth add in rest of milk.
Bring to a boil, stirring to keep mixture smooth, takes about 3 minutes.
Grate the cheese in to a bowl and add to the saucepan while stirring the sauce
Beat eggs in a bowl, add to saucepan while stirring the sauce.
Heat until sauce thickens, don't boil.