Step 1

Wash and chop tomatoes into bite-size pieces. Cook in a slow cooker on low heat for 6 hours, until cooked and soft.

Step 2

Place the food mill over a large bowl and run the tomatoes through it. Store the purée in wide-mouth jars and freeze or cook down before storing.

Step 3

Blanch and peel the washed tomatoes. Core them, score the bottoms with a shallow "X" and gently put the tomatoes into a pot of boiling water until the skins begin to pull away (about 1 to 2 minutes). Immediately transfer the tomatoes to an ice bath—a large bowl filled with cold water and ice cubes. When the tomatoes are cool enough to handle, pull the skins off with your fingers. They should slip off easily.

Step 4

Cut the tomatoes in half. With a spoon, remove the seeds. Chop the tomatoes and cook in a slow cooker on low heat for 6 hours, until cooked and soft.

Step 5

Purée the tomatoes with an immersion blender, standard blender or food processor. Store the purée in wide-mouth jars and freeze or cook down before storing.

Step 6

Cut the tomatoes in half. With a spoon, remove the seeds. Chop the tomatoes and cook in a slow cooker on low heat for 6 hours, until cooked and soft.

Step 7

Purée the tomatoes with an immersion blender, standard blender or food processor. Store the purée in wide-mouth jars and freeze or cook down before storing.

Step 8

Simmer the purée gently on medium-low heat for an hour or until it has reached your desired consistency. Stir often. You can also cook it down in the slow cooker at low heat for 8 hours. Avoid cooking it for longer than 8 hours. Cooking tomatoes for too long in a slow cooker can result in a burnt taste.