1. Heat olive oil in a heavy-bottomed pot. Add onion and garlic and cook on low heat for 5 minutes, taking care not to burn.
2. Add the tomatoes and reserved juice, salt, paprika, cumin and chili powder to the pot. Simmer, covered, on low heat for 15–20 minutes. Blend with an immersion blender or transfer to an upright blender and purée until smooth.
3. Return the purée to the pot; add vinegar and sugar. Adjust spices to taste. Simmer on low, stirring often, until ketchup thickens, about 30 minutes.
About this recipe
This ketchup will last for up to 3 months in the refrigerator and for 1 year if canned; it can also be frozen.