Ingredients:
- 1.5 lbs sirloin steak, thinly sliced against the grain
- 2 tbsp avocado oil
- 1/2 tsp sea salt
- 1/2 tsp cracked black pepper
- 8 oz baby bella mushrooms, sliced
- 3 cloves garlic, minced
- 1 cup beef broth, low sodium
- 1 tbsp Dijon mustard
- 1/2 cup full-fat sour cream
- 1 tbsp butter
- 2 tbsp fresh parsley, chopped
- 1/4 cup grated Parmesan cheese
Instructions:
- Pat the beef strips completely dry with paper towels and season with salt and pepper.
- Heat avocado oil in a 12-inch cast iron or stainless steel skillet over high heat until it just begins to smoke.
- Add beef in a single layer, working in batches, and sear for 1-2 minutes per side until mahogany-colored. Remove beef to a plate and set aside.
- Reduce heat to medium. Add butter to the same pan.
- Add sliced mushrooms and sauté until they release their moisture and turn golden brown.
- Stir in the minced garlic and cook for 60 seconds until fragrant.
- Pour in the beef broth and Dijon mustard, scraping the bottom of the pan to release the brown bits (fond).
- Let the liquid simmer and reduce by half.
- Turn the heat to LOW. Slowly whisk in the room-temperature sour cream until the sauce is thick and velvety.
- Return the beef and any accumulated juices to the pan, stirring gently until heated through.
- Garnish with chopped fresh parsley and grated Parmesan cheese.