Cut a small cross in the ends of the tomatoes. This will make it easier to peel the skins off. Bring a pot of water to the boil, add tomatoes and bring to the boil again. After a few minutes test to see if the skins will peel off easily. If they don't, cook for another few minutes. Drain the boiling water and fill up the pot with cold water. Using tongs/a fork (they will be really hot) peel the skins off the tomatoes and discard.
Add the peeled tomatoes and all other ingredients to a pot and bring to the boil, then simmer for 20 minutes.
Remove the bay leaf and then using an immersion blender, whizz up the sauce until it is smooth. If you don't have an immersion blender you can transfer the sauce to a regular blender instead.
Continue to cook for another 20 minutes until sauce has thickened.
Allow to cool then refrigerate. Sauce will keep in the fridge for a few weeks. It will also freeze well.