In a large bowl, add ground chuck, breadcrumbs, fresh parsley, milk, salt, cracked black pepper, and 1 tsp paprika. Use your hands to mix that together but DON'T OVER MIX IT). Now begin rolling the meat into meatballs (about 2 inches big) and set them aside on a plate.

Heat up a cast iron or pan and add in butter and olive oil. Once the butter is melted, add in all the meatballs. Flip the meatballs at least once or twice until they are browned and almost cooked through on medium heat. Once they are almost cooked, remove them from the pan and set them aside on a plate.

In the SAME pan with the excess oil, add in 2 more tbsp of butter. Also, add in onion powder, garlic powder, 1 tsp paprika, and stir that together with the butter. Now, add in the sliced mushrooms and onions and toss everything together. Saute that on medium heat until they are golden, translucent, and soft.

Once those veggies are golden and soft, add in salt & cracked black pepper and shake over the flour. Whisk that continuously for 2 - 3 minutes and then pour in the worcestershire and beef broth. Whisk continuously for another 2 - 3 minutes until the sauce begins to thicken up.

Next, lower the heat to a low simmer and stir in the sour cream. Then, add the meatballs back into the pan with all the accumulated juices and let the meatballs simmer in the sauce for about 5 -10 minutes. Garnish it with some fresh parsley and serve over mashed potatoes. Enjoy!