Green Tomato Relish

1 peck (12 1/2 lbs.) green tomatoes, cored
12 large onions
2 Tbsp. noniodized salt
2 qts. vinegar
4 lbs. brown sugar
2 Tbsp. celery seed
2 Tbsp. mustard seed
2 Tbsp. allspice

Grind tomatoes and onions. Add salt. Let mixture stand overnight in a cloth bag to drain. Next day, mix remaining ingredients with tomatoes and onions. Bring mixture to boil and boil gently for 30 minutes. Remove from heat and seal in sterile jars. Process 10 minutes in boiling water bath. Makes 12 pints relish.