Mix salt, pepper, mustard, vinegar, oil and honey well in a bowl and beat lightly until frothy. Finely chop the mint and stir in. It is best to leave the dressing in the refrigerator for half a day.
If you like, you can replace the vinegar with lemon juice. If you like the dressing a little more hearty, you can stir in some very finely chopped spring onions.