How to Make It
In a large saucepan, heat the vegetable oil over medium heat. When it’s warm, add the onion and garlic and sauté, stirring often, for 5 minutes. When the onion starts to become translucent, add the tomato paste, curry powder, paprika, cayenne, cinnamon, and allspice. Stir to combine and cook for 1 minute.
Add the diced tomatoes, maple syrup, and vinegar and season with the salt and black pepper. Bring the sauce to a simmer, then reduce the heat to medium-low and cook, uncovered, for 30 to 35 minutes, until reduced and thickened. Give the ketchup a stir every few minutes so it doesn’t catch.
Remove from the heat and pulse in a blender until smooth (or puree directly in the pot using an immersion blender). Let cool completely, transfer to a jar, and refrigerate overnight so all those flavors can really get to know each other. The ketchup will keep in an airtight container in the fridge for up to 1 month