A sore throat tags along with several illnesses and can be particularly annoying. If you need relief from the pain, you probably have the primary ingredient sitting in your fridge: mustard. Farmer's Almanac offers the full recipe:
Grind one tablespoon of mustard seed and combine with the juice of half a lemon, one tablespoon of salt, one tablespoon of clear honey, and 1 1/4 cups of boiling water. Leave this mixture, covered, for 15 minutes and use as a gargle.
Sore Throat Secrets [Farmer's Almanac]