Melt butter in an oven safe pan over medium heat. Add the onion and saute until translucent, about 6 minutes.

Meanwhile, beat the eggs, heavy cream, dill, salt, and pepper together in a large bowl.

Sprinkle salmon and cubed cream cheese evenly over the onions.

Pour whisked egg combo over the top, and quickly use a spatula to lift up the onions and salmon to allow the eggs to trickle underneath. Place a lid on over your pan, and continue to cook your frittata until the edges set, should be 10-12 minutes.

Adjust your oven rack so the top rack is 10" away from the bottom of your broiler, and turn your broiler to high. Pop your pan in the oven until the center is completely set, should be 5-8 minutes, but check frequently so it doesn't burn. Serve immediately and enjoy.