5500 ml kilner jars
By William Lander, Shaun Searley and Daniel Morgenthau
Although we use this in the tartine you can also use it as a marinade for white or dark meats or as a dipping sauce for our confits.
Chop the tomatoes and peel and dice the onions and apples. Combine all of the ingredients apart from the sugar in a heavy-based saucepan and simmer for 3 hours, stirring occasionally.
Add the sugar and continue to simmer for a further hour, stirring more frequently as the ketchup starts to stick to the bottom of the pan. Blend the ketchup to a smooth purée using a stick blender and then