Use a knife to quarter the blood oranges (and lemon) and take out the pips. Peel off some of the rind if you prefer less in your marmalade. Weigh the fruit in the Thermomix and chop for 5 secs on speed 5.Add the water and cook for 10 mins at 100 degrees on speed 2.Weigh in the sugar and cook again for 20 mins at 100 degrees on speed 2.Pour into sterilised jars.