Beef

• You will need 1 lb. of beef sirloin for this recipe. You can substitute the sirloin for ground beef as well. Cut into small strips about 2 inches by 1 inch by 1/8 inch in size and season with salt and pepper. Preheat a large skillet over medium heat up to four minutes and then raise heat to high. Pour 1 tbsp. of vegetable oil in the pan and once it's heated up, add the beef to the skillet. Saute the beef until browned, about one to two minutes, and add some salt and pepper to season. Take the beef out and let it rest on a plate.
  
  

Mushrooms

• Return the skillet to medium heat and melt 2 tbsp. of butter until it starts to foam. You will need 12 oz. of button mushrooms cut into halves. Add the mushrooms to the skillet and cook for seven minutes or until well browned. When they're done, remove and add to the plate with the beef.
  
  

Sauce

• Use one medium yellow onion thinly sliced or 1/3 cups of chopped shallots if you want a more mild taste. Heat 4 tbsp. of butter and add the onions. Stir and cook until lightly caramelized, about five minutes. Add 1 tbsp. of tomato paste and cook one minute, then whisk in 2 tbsp. of all-purpose flour and stir for another minute. Pour in 2 cups of beef broth and bring to a boil, whisking constantly. Once it boils, remove from the heat and whisk in 1/4 cup of sour cream, 2 tsp. of mustard and 2 tsp. of freshly squeezed lemon juice. You can also substitute the sour cream with yogurt. Add salt and pepper and let the sauce rest while covered.
  
  

Noodles

• Bring a large pot of water to boil and add a generous amount of salt to season the water. Add one 12 oz. package of egg noodles and cook until tender. Substitute noodles for a cup of white or brown rice. When the noodles are done, drain and transfer to a large bowl, add 2 tbsp. of unsalted butter and season with salt and pepper. Combine with all the other ingredients and sauce in the skillet to reheat. Add 1 tbsp. of chopped flat-leaf parsley and serve.