Preheat oven to 375° and position a rack in the center.
Allow about an hour for the puff pastry to thaw at room temperature.
Unfold one sheet and cut into 4 squares.
Using a fork, combine one egg yolk with one tablespoon water.
If using a package of of one long smoked sausage, cut the sausage links to fit the pastry sheets. If using individual packaged sausages you won't need to cut them. Lay each link along the bottom side of each pastry square. Using a silicone brush, brush a layer of the egg mixture on the top end of the pastry square.
Roll the sausage bundles pressing the seam together and place them on a baking sheet, seam side down. Freeze the sausage bundles for 10 minutes.
Remove from freezer and cut the sausage bundles into 1/2 inch slices.
Place the sliced sausage in a blanket into mini-muffin pans. Bake for about 25 minutes or until pastry is starting to become golden brown.
While they're baking, combine the mustard and chutney in a small bowl. Once they're baked, remove them to a platter and while hot, use a small spoon to add a dollop of the sauce to each slice.