Melkeringe is a sour milk product, which is similar in consistency to pannacotta. In the olden days, melkeringe was made immediately after the cows had been milked, using strained milk which had not had time to cool down. It was poured into a milk ring which was a round, low, wooden container.
It was then set aside to sour at room temperature for approx. 24 hours. At the end of the souring process, the container was chilled at a lower temperature until it was served. It is now more common to make melkeringe using the method I have employed here, i.e. by adding a bacterial culture to the milk.
Heat up the milk and sugar to just below boiling point and cool the mixture to around 80 Fahrenheit (25 Celsius). Whisk in the cultured milk. Pour the mixture into glasses and leave them to stand at room temperature for 1-2 days. Cool the milkeringe and serve it with the crushed honey cookies and plums.