Place the tomatoes in a bowl of boiling water for a couple of minutes. Then drain.
Use a sharp knife to pierce the skin then peel the skins, cut the tomatoes in to quarters over a bowl (to catch any juice) and remove the stem part.
Place the tomatoes in to pre - sterilized jars together with a basil leaf, 1/2 teaspoon of salt and a squeeze of lemon juice. *** Fill the jars 3/4 full with the tomatoes. Using a wooden spoon, push down gently on the tomatoes to remove any excess air bubbles. Then any excess juice you may have from cutting the tomatoes, add to the jars, leaving 1/2 inch of space at the top.
Wipe jar rim removing any food residue. Centre hot sealing disc on clean jar rim. Screw band down. Place jars in the canner (boiling pot). 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 then reduce heat to a simmer and start the cook time for 40 minutes.
You may need to place a clean cloth on the base of the cooking pot to stop the jars from 'shaking' during simmering.
When processing time is complete, turn stove off, 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.