Roasted plum mayonnaise
Preheat the oven to 180°C.
Line a small tray with baking parchment. Mix the plums, sugar, pinch of salt, a teaspoon vinegar in a mixing bowl, then lay on the lined tray. Bake for 10 minutes until the plums the soft and ready to fall apart.
Leave the cool. Put the plums in a blender and blend to a paste. Switch off then add the 2 egg yolks, the rest of the vinegar, the salt, and the mustard. Start the blender again on a slow or up to medium speed, then add the oil in a slow drizzle. Make sure the oil is fully incorporated before adding more.
Once all the oil is added, check the consistency. If it is too thick, you may add 1 teaspoon or more of cold water. If you are happy with this bright pink happy blobby Ness, then just enjoy and celebrate.