In a large stainless steel pot, combine onions, peppers, tomatoes, garlic and 1 cup vinegar.
Bring everything to a boil together and simmer for at least 25 min until all the vegetables are soft enough to mash with a wooden spoon.
Remove the garlic bulb and mash the remaining vegetables in a hand blender. Then pour the puree repeatedly into the saucepan and add the remaining cup of vinegar, brown sugar, and salt. Tie all the other spices in a piece of muslin cloth and put it in the cooking pot as well. Thereupon bring the mixture to a boil and simmer for 2 hours, stirring continuously, until it thickens considerably.
Re-season the tomato ketchup and pour into four warm 1/2 liter jars. Seal the jars and place in a boiling water bath for 10 min.
Makes 2 liters of ketchup.
Tip: Stock up on high-quality seasonings – it pays off!