Step 1

Place ingredients in a 4.5-litre (18-cup) slow cooker. Cook, covered, on high, for 4 hours.

Step 2

Discard bay leaves; season to taste. Using a stick blender, blend sauce until smooth.

Step 3

Increase heat to reduce setting on high; boil, uncovered, for 10 minutes or until thickened slightly.

Step 4

Pour sauce into hot sterilised bottles (see glossary, page 235); seal immediately. Label and date bottles when cold.