Melt some cooking fat in a skillet over medium-high heat.
Cooking fat
Sauté the mushrooms, garlic, and onions until they are lightly browned, about 4 to 5 minutes.
2 cups brown mushrooms, 2 garlic cloves, 1 onion
Pour in the stock and whisk, scraping the bottom of the pan.
2 ½ cups beef stock
Season to taste, add the rosemary, and cook until the sauce reduces. You can also add 1 tbsp. tapioca with 1 tbsp. of water to the sauce to thicken it.
1 tbsp. fresh rosemary, 1 tbsp. tapioca starch, Sea salt and freshly ground black pepper
In a skillet, melt more cooking fat over medium-high heat.
Season the steaks with sea salt and freshly ground black pepper on both sides.
2 to 4 steaks of your choosing, Sea salt and freshly ground black pepper
Place the steaks in the skillet and sear both sides for 2 to 3 minutes, depending on the thickness.
Turn the steaks every minute, basting regularly with the fat, until it reaches your desired doneness.
Remove the steaks from the skillet and let them rest for a minute or two before serving.
Serve The steaks topped with mushroom sauce.
Sprinkle with fresh parsley if desired.