Combine spices with vinegar; bring to a rapid boil for 5 minutes. Stir in sugar, stirring until dissolved.
Reduce heat to a simmer and stir in tomatoes and onions; simmer until nearly tender (about 5 minutes), remembering that vegetables will continue to cook for another 20 minutes or so while being processed and cooling off.
Ladle into clean hot jars leaving 1/4" headspace. Wipe rims of jars clean. Adjust 2 piece caps. Process in a boiling water bath for 10 minutes.
Submitted by: CM