Lightly toast 2 slices of sourdough.

Place toast on a tray or pan that can go under the grill.

Warm the thermidor sauce in a pan.

Flake the crab in to the sauce and warm through stirring gently so the crab gets nicely covered.

Spoon the crab mixture on to the toast.

Place under a hot grill.

Remove once bubbling away and starting to colour.