Place 8 clean 250 ml or 4 clean 250 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. Keep jars hot until ready to use. Preheating Bernardin® lids is not advised.

The sealing compound used for our home canning lids performs better at room temperature than it does pre-heated in simmering water (180°F). Simply wash lids in hot, soapy water, dry, and set aside until needed.

Preheating can lead to less vacuum being achieved during water bath canning, and to buckle failures during pressure canning. Grill or broil dried chilies, turning frequently, just until they start to char on all sides. Discard stems and seed pods.

Place roasted chilies in bowl; add 2 cups (500 ml) boiling water. Place weight over chilies to keep them submerged. Let steep. Grill or broil tomatoes, peppers, onions and garlic cloves 15 to 20 minutes, turning to roast all sides.

Peel & chop tomatoes, peppers, onion and garlic; place in a large stainless steel saucepan. Purée chilies with soaking water; add purée to roasted vegetable mixture with sugar, salt and vinegar. Stirring frequently, bring to a boil; continue cooking 15 minutes.

Ladle salsa into a hot jar 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 salsa. Wipe jar rim removing any food residue. Centre hot sealing disc id 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 salsa. 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; 250 ml jars - 15 minutes; 500 ml jars - 20 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.

Processing: At altitudes up to 1000 ft (305 m), process -boil filled jars; 250 ml jars - 15 minutes - 20 minutes.

Altitude-adjusted processing table: At altitudes up to 1000 ft (305 m), process -boil filled jars; 250 ml jars - 15 minutes