How to Make Ketchup

Step 1: Puree the tomatoes
Pour the can of tomatoes, along with their liquid, into a blender and mix until smooth.

Step 2: Cook an onion
Heat the oil in a large saucepan and cook the onion until it’s soft, about eight minutes. 

Step 3: Add remaining ingredients
Add the pureed tomatoes, tomato paste, sugar, vinegar, and spices. Simmer, uncovered, until very thick, about one hour, stirring occasionally. 

Tip
Be especially vigilant about stirring towards the end, when the sauce begins to thicken.

Step 4: Puree the mixture
When the mixture has cooled down, pour it into the blender and puree it until smooth. 

Step 5: Cover and refrigerate
Put the ketchup in a covered container and chill at least two hours before using. 

Tip
Experiment with different flavors by throwing a couple of peeled and chopped green peppers, apples, or mangoes into the blender along with the tomatoes, or spicing up the recipe with a finely diced jalapeno pepper. 

Step 6: Enjoy!
Enjoy your homemade ketchup! You'll have about a pint. It will stay good in the fridge for up to three weeks. You also can freeze it.