What a nice change for my lunch..I only used 4 slices of bread so cut down the butter and mustard by a little. I used dijonaise and edam cheese...added 1/4 cup of milk to the egg and that worked out fine.
These made an quick, light, easy and delicious lunch. I think the secret is to use good quality bread. I was a little timid about the mustard and used the mildest we had. In retrospect, I think something a little stronger would have been better. Nevertheless, they were delicious and while this recipe would work with most cheeses, I recommend trying it with Gouda.