Here’s how you do it: Take two big jars with tight-fitting lids (just no patent lids with those rubber thingies) and fill
them up with sliced tomatoes and herbs or, as I did, add sliced red peppers and roughly chopped garlic. Make sure you stuff the glasses as much as possible, as the mixture will reduce quite a lot (see picture).
Add a splash of olive oil, whole pepper corns and salt and finally close the lids tight, but then un-screw the lid slightly so the heated air can leave the glass during the cooking time. Leave it in the oven on 110 degrees for four hours [sic!] or until the content has reduced approximately 30% and you can see it bubbling slightly. Then close the lid completely.
These last steps ensure the preservation because the boiling kills off the germs and the lid seals it all in (well, duh!). So far, my glasses have survived on the shelf for 10 days without showing
any signs of old age (Mrs. Plum says she keeps hers all winter, though the sheer attractivity of them makes them last for a much shorter while).
Must admit though, that I’m so much of a disbeliever, that I simply have to check the status from time to time anyway…which takes us back to day five of my food journal. I just heated the preserve in a saucepan and didn’t have to change a thing. The tomatojuice in the sauce had such a deep and sunny flavour and the red
peppers almost tasted slightly smoked, so all the work was done. I recommend just serving it as it is with pasta and a bit of parmesan cheese. Nothing else to ruin the sweet simplicity of slow-cooked vegetables in season.