Cut all in small pieces (except onions). Cover with 1 tbs salt and 1 quart water. Boil, then drain.
Mix dry ingredients in a little water. Add to cucumber mixture. Add vinegar. Boil 20 minutes.
Thicken with corn starch. Seal while hot, like you would jam
If you cant find Dans dry mustard, substitute any good quality dry mustard. This recipe has won awards at the county fair!