Lay out the grated cheese and place a layer of cornflakes on top. Finish with a layer of cheese creating a cornflake sandwich. Place under the grill on a pastry mat until the cheese melts.
Remove and let it cool then mould over the base upside down bowl to form a basket. Leave to cool.
Place the watercress, salmon into the cornflake basket and garnish with dill and crème fraiche.