Roughly chop or shred smoked salmon and dice red onions.
Add butter to a small omelette pan until melted over medium-high heat and then add the smoked salmon, red onions, and capers. Try to distribute the fillings evenly over the surface of the pan. Cook for about 2 minutes.
Meanwhile, whisk eggs together with milk with a fork to scramble them.
Pour eggs over the filling mixture in the pan. Turn heat down to medium and cook eggs. As the eggs cook, use a flat spatula to push the cooked eggs to the center and tilt the pan slightly to let the uncooked eggs flow to the outside.
Cook the eggs until they are almost all the way cooked. There will be a very thin layer of uncooked egg on the top and that’s fine.
Add cream cheese to one half of the omelette and use a spatula to fold the egg over to form an omelette.
Cook omelet for another 30-45 seconds on each side to melt the cheese and finish cooking the eggs.