Slice the steak thinly and sprinkle with sea salt and paprika.

Heat the avocado oil over medium heat in a cast iron or stainless steel skillet. Add the onion and saute, stirring occasionally, until onion is translucent and beginning to brown, about 5 minutes.  Transfer the onion to a bowl and set aside. Place the skillet back on the burner. 

Place the slices of beef on the hot skillet in a single layer and sear until golden-brown, about 1 to 2 minutes. Use tongs to flip the slices and sear another 30 seconds. Transfer seared meat to a bowl and set aside (note: You’ll likely need to sear the meat in two batches, depending on the size of your skillet).

Wipe out skillet with a paper towel, add another 1 to 2 tablespoons of avocado oil, and place back on the burner. Add the sliced mushrooms and cook, stirring occasionally, until golden-brown, about 3 to 5 minutes.

Add the beef broth to de-glaze the skillet and bring to a full boil. Cook 2 to 3 minutes, until liquid has reduced slightly.

Serve beef stroganoff with steamed white rice, gluten-free pasta, zucchini noodles, or side dish of choice with chopped parsley.