Pull outer husks back from each corn cob and discard the fine ‘hair’, but reserving the husk to use like a handle. Place on an open grill or flame and turn occasionally until well cooked and blackened.
Place mayonnaise, sour cream, and cumin into Thermomix bowl and blend 6 sec/speed 6.
Allow corn to cool a little and then spread some of the mayonnaise mixture onto each cob. Top with all remaining ingredients to taste and eat immediately.