Place about 4 cups of washed/stoned/roughly chopped fresh plums in a blender and blend until pulpy. Cook with a little bit of water (1/4 cup or so) and about 3 cups of sugar for about ½ hr or until it allows you to scrape a spoon through it and it separates (keep an eye on it and stir often or it will burn). I use a heat diffuser mat under the pan which helps to stop it catching. You can either make it as individual serves or pour the whole lot into a lined lamington pan and let it set in the fridge. Don’t do what I did and line your tray with plastic wrap (it stuck) - you might want to try baking paper instead. Enjoy with a nice brie and a glass of wine!