Cut the onion into thin slices and combine with the garlic and tomatoes into a large glass bowl. Sprinkle the pickling salt over the tomatoes and onions and mix well.
Cover and allow the vegetables to sit in your refrigerator for at least 2 hours, preferably overnight.
Remove the vegetables, put in a colander and rinse lightly.
In a large pot combine the cider vinegar, water, turmeric, celery seed, mustard seed, and sugar. Bring the mixture to a simmer over low heat.
Slice the desired amount of hot peppers into thin slices and stir into the tomatoes.
Pack the jars with the tomatoes, onions and peppers. Leave about a ½ inch from the top of the jar.
Using a funnel, pour the hot vinegar and spice mixture into the jars.
Check for air bubbles and remove them with a non-metal utensil.
Wipe the rims clean and securely attach the lids.
Process in a boiling water canner for 20 minutes.
Or, seal in a 250 degree oven for 25 minutes and then remove and let cool.
Makes 2 1-quart jars or 4 pints. As with all pickles, it's best to wait 4-6 weeks or so before you indulge to make sure they have that pickley taste.