1. To peel tomatoes: bring a pot of water to a boil. Prepare a bowl of ice water. Blanch tomatoes for 20 seconds, then plunge into ice water. Drain, peel, halve, seed, and chop the tomatoes.

2. Combine vinegar and sugar in a saucepan and bring to a boil over high heat. Boil until reduced by half, about 7 minutes. Add the tomatoes and Worcestershire and bring back to a boil. Reduce heat to low and simmer, stirring frequently, until tomato mixture is dark brown and very thick, about 20 minutes.

3. Transfer jam to a blender or food processor, add olive oil and blend on high until smooth, about 2 minutes. Season with salt and 2-4 gratings of nutmeg. Transfer to a clean container and refrigerate. The jam will keep for 3 weeks in the fridge.