The oils that  give horseradish its pungent nature are quite similar to those found in mustard. Our horseradish is pure and gives the most wonderful flavour.
For a thick, sharp horseradish sauce, mix 1 part powder with 3 parts water.  For a thinner sauce, thin out with yoghurt, lemon juice or vinegar.
Horseradish is of course the perect sauce to have with roast beef !