Using the same pan, add the remaining ghee. Lay the sirloin pieces in a single layer and brown and brown the sirloin on each side. Be careful not to overcrowd the pan or they will not brown. Transfer the meat to the bowl with the mushrooms and then repeat with remaining meat.
Pour 1/2 cup broth of chicken broth into the now empty pan. Scrape all of the brown bits up from the bottom of the pan and bring the broth to a simmer. Simmer until broth is reduced by half, about 3-4 minutes. Pour the broth into the bowl with the mushrooms and meat.
Return the skillet to the stove over medium-low heat. Add the butter. After the foaming subsides, add the onion, tomato paste and sugar. Stir occasionally, and cook for about 6 minutes until the onions turn golden brown. Stir in the arrowroot and continue to stir for about 30 seconds. Add the remaining 1/2 cup broth and the white wine. Bring the sauce to a boil and then reduce to a simmer for 2 minutes.
Place the sour cream into a small bowl and add 1/2 cup of the sauce to the sour cream and stir (this step will keep the sauce from curdling). Add the sour cream mixture to the pan, along with the beef and mushrooms. Stir until combined. Season with salt and pepper to taste. Serve over baked potato, or gluten-free egg noodles.