Combine the cubed ham, shredded cheese, scallions, mustard and horseradish in a bowl .
Roll out the puff pastry and make 36 2 1/4 in rounds on floured surface. Form into mini muffin tins. You should butter them first if the muffin tins are not stick-free!
Place about a teaspoon of ham mixture onto the pastry cup. Beat the eggs and the cream together and then pour over the ham mixture, barely covering it. There should be just the right amount of the cream mixture to use in all 36 bites, so I generally fill 1/2 way up and then go back around
Place in 375 oven for 20-25 minutes. They will puff up and then collapse. Remove from the tins by riunning a knife around the edge and serve.