This is a great way to put those early green tomatoes to use. Not as  sweet as bread and butter pickles, but tart like dilled, green tomato  pickles are the perfect relish for any lunch plate.
   Makes about 9 x 500 ml jars.
     7 lb (3.2 kg) green plum tomatoes, about 35 medium
   2 medium cooking onions 
    1/4 cup (50 ml) pickling salt
     2 medium sweet red peppers
     1 lemon
     1 tbsp (15 ml) celery seed
     3 tbsp (45 ml) mustard seed
     1 tbsp (15 ml) Each: green peppercorns, dill seed
     4 cups (1000 ml) vinegar
     2 cups (500 ml) water
     1 cup (250 ml) granulated sugar
   • Day 1: Thoroughly wash and remove cores from tomatoes. Thinly slice  tomatoes and onions crosswise, sprinkle with 1/4 cup (50 ml) pickling  salt; cover and let stand 12 hours in a cool place. 
  • Day 2: Place 9 clean 500 ml mason jars on a rack in a boiling water  canner; cover jars with water and heat to a simmer (180°F/82°C). Set  screw bands aside. Heat SNAP LID® sealing discs in hot water, not  boiling (180°F/82°C). Keep jars and sealing discs hot until ready to  use.
   • Thoroughly drain tomatoes and onions; do not rinse; set aside tomatoes and onions.
  Wash and seed red peppers; slice into thin strips. Wash and thinly slice lemon; remove seeds; set aside.Tie celery seed in a square of cheesecloth, creating a spice bag.In a large, deep stainless steel saucepan, combine reserved tomato  mixture, red pepper, lemon, spice bag, mustard seed, peppercorns, dill  seed, vinegar, water and sugar; mix well. Bring to a boil, boil gently 1  minute; remove from heat. Pack pickles into a hot jar to within 3/4 inch (2 cm) of top of jar.  Add hot cooking liquid to cover pickles to within 1/2 inch (1 cm) of  top of jar (headspace). Using nonmetallic utensil, remove air bubbles  and adjust headspace, if required, by adding more cucumbers and hot  pickling liquid. Wipe jar rim removing any food residue. Centre hot  sealing disc on clean jar rim. Screw band down until resistance is met,  then increase to fingertip tight. Return filled jar to rack in canner.  Repeat for remaining cucumbers and hot pickling liquid.When canner is filled, ensure that all jars are covered by at least  one inch (2.5 cm) of water. Cover canner and bring water to full rolling  boil before starting to count processing time. At altitudes up to 1000  ft (305 m), process –boil filled jars – 15 minutes.*When processing time is complete, remove canner lid, wait 5 minutes,  then remove jars without tilting and place them upright on a protected  work surface. Cool upright, undisturbed 24 hours; DO NOT RETIGHTEN screw  bands. After cooling check jar seals. Sealed discs curve downward and do  not move when pressed. Remove screw bands; wipe and dry bands and jars.  Store screw bands separately or replace loosely on jars, as desired.  Label and store jars in a cool, dark place. For best quality, use home  canned foods within one year.