• Wash the tomatoes well
• Sort them: keep the hard ones to prepare concasse, throw away the rotten ones, etc..
• Remove the stems and any bruises or imperfections
• Cut the tomatoes and throw them in a tomato churning machine
• Add a handful of sea salt to the tomatoes as they are churned into a purée
• Push the tomato purée through a sieve
• Squeeze out all the juices and throw away the remaining seeds and skin

In a large shallow tin-lined copper pot

• Pour the pure tomato juice through a sieve into a large tin-lined copper pot which is properly set on the fireplace
• Monitor the fire and add the necessary wood to keep the heat consistent
• Once the juice starts boiling and thickening, start stirring the pot to make sure the paste doesn't stick to the pot and get burned
• Throw in a handful of sea salt
• Once a while, clean the sides of the pot with a flexible spatula
• After the mixture starts to thicken, taste to adjust the salt
• Once the mixture thickens and resembles a paste, remove it from the heat

In clean dry jars

• Instantly fill the canning jars with the hot tomato paste
• Tap the jars to make sure all air comes out
• Immediately, close the lids tight