Heat butter in a large skillet over medium heat.

Add the chopped onion and sauté until golden, about 8-10 minutes.

Add sliced mushrooms and sweet Hungarian paprika.

Cook, stirring occasionally, until mushrooms start to wilt, about 5 minutes.

Whisk eggs, salt, and pepper in a small bowl.

Reduce heat to low.

Pour the egg mixture over the top of veggies in the skillet.

Cook the omelet slowly for about 10 minutes, or until done enough to flip over without running.

Flip and cook for 3-4 minutes on the other side.

Cut the omelet into wedges and serve with a dollop of sour cream and a sprinkling of parsley and green onion.