Place the spinach in a microwave safe bowl and microwave for one minute on high. If the spinach is not completely reheated, stir it and microwave again for 30 seconds. Drain the spinach.
Crack the eggs into a blender. Pour in heavy cream, add spinach and season with salt and pepper. Blend everything together until homogeneous.
Melt a teaspoon of butter in a medium skillet. Gently pour half of spinach-egg mixture into the skillet and cook until just begin to set.
Arrange smoked salmon slices on top, spread with cream cheese, sprinkle with chopped dill and begin to roll the omelette carefully.
Once you have rolled up the omelet, put it back to the edge of the skillet.
Pour the other half of spinach-egg mixture into the skillet, arrange remaining salmon slices on top and roll the omelette when the egg is set.
Transfer to a serving plate and serve immediately sprinkled with more chopped dill.