Makes about 8 pints.
Grind the onions and peppers together in a meat grinder, using the coarsest blade. Mix the ground vegetables and salt in a bowl, cover with a lid or plate and weight the top. Leave for 3 hours, then drain. Put the vinegar, sugar and spices in a large pot and stir until the sugar is dissolved. Cut off the stems of the okra, add to the pot with the drained vegetables and cook over low heat until the vegetables are very hot and the liquid almost to a boiling point. Do not allow to boil. Ladle into hot, sterilized preserving jars, cover and seal. Store in refrigerator or cool place for 4 months before using.