01 - In a shallow dish, whisk together the all-purpose flour, kosher salt, black pepper, and smoked paprika until evenly combined.
02 - Press each cube steak into the seasoned flour mixture, coating both sides thoroughly. Shake off any excess flour and set the dredged steaks aside on a clean surface.
03 - Heat the vegetable oil and 1 tablespoon of butter in a large skillet over medium-high heat until the fat shimmers. Carefully lay the coated steaks in the skillet and sear for 2 to 3 minutes per side until a deep golden-brown crust forms. Work in batches to avoid overcrowding the pan. Transfer the browned steaks to a plate and set aside.
04 - Reduce the heat to medium and add the remaining 1 tablespoon of butter to the same skillet. Add the sliced onions and cook for 5 minutes, stirring occasionally, until softened and lightly caramelized. Add the sliced mushrooms and continue cooking for 3 minutes until they release their moisture and begin to brown.
05 - Pour the beef broth and Worcestershire sauce into the skillet, using a wooden spoon to scrape up any browned bits from the bottom of the pan. Bring the liquid to a gentle simmer.
06 - Return the seared cube steaks to the skillet, nestling them down into the onion and mushroom mixture. Reduce the heat to low, cover with a tight-fitting lid, and let simmer for 30 to 35 minutes until the beef is fork-tender and the gravy has thickened.
07 - If using, stir in the heavy cream during the final 5 minutes of cooking for a richer, silkier gravy. Taste the gravy and adjust the seasoning with additional salt and pepper as needed.
08 - Plate the cube steaks while hot and spoon the onion-mushroom gravy generously over the top. Serve alongside creamy mashed potatoes, steamed rice, or buttered egg noodles.