Preheat your oven to 375°F.
Spray a 12-cup muffin pan with non-stick spray. This is a must, otherwise you will never get these things out!
Using a 3" round biscuit cutter, cut 9 circles out of your puff pastry sheet. Knead the scraps together and roll the remaining dough large enough to cut two more circles. Take the last remaining scraps to make your final circle.
Take one circle and gently stretch it bigger, being careful not to tear it. Press it into the muffin tin, making sure it goes up the sides as well. Repeat with all the dough. Be sure there are no holes or tears. You don't want the egg mixture to get under the pastry.
Place about a tablespoon of smoked salmon into each cup.
Place about a tablespoon of shredded cheese on top of the salmon.
In a small bowl combine the eggs, half-n-half or milk, and the salt and pepper. Pour approximately 1-2 Tablespoons into each cup over the salmon and cheese. Try not to overfill or the egg mixture will get underneath the pastry and make it stick to the tin.
Bake at 375°F for 20-22 minutes or until lightly golden brown.
Top with green onions, if desired.