Place tomatoes, onion, peppers and garlic in a pot and bring to a simmer. Cook for 15 minutes, until peppers are soft.
Add sugar, vinegar, salt and spices and continue to simmer until excess water has cooked away and mixture is sauce consistency.
Jar chilli sauce following proper canning procedures, including boiling the filled jars (without submerging lids) for 15 minutes.
Store chilli sauce in a cool dark place for up to a year.