Grilled Orange Egg Custard

1 Orange (or Grapefruit)
2 T Milk
1 Large egg Sugar & cinnamon, To Taste
With the navel at the bottom, slice off the top of the orange & dig out all the pulp and fruit (to eat)... save the "orange cup"... in fact, serve oranges during dinner & get everyone to save their orange cups for this.
Crack egg into a bowl with the milk, sugar & cinnamon and gently whisk it a little with a fork, but don't over mix, you want the lumps of smooth egg white when it's cooked.
Place egg mixture in the orange cup & place them over a grilling stand over Embers (not the fire).. wait till egg looks cooked, but not hard.