01 - In a shallow dish or wide bowl, combine the flour, salt, black pepper, and paprika. Mix thoroughly until evenly blended. Reserve 2 tablespoons of the seasoned flour mixture and set aside for thickening the gravy later.
02 - Pat each cube steak dry with paper towels. Working one at a time, press each steak firmly into the seasoned flour, coating both sides completely. Shake off any excess flour and transfer to a clean plate or cutting board.
03 - Set a large skillet over medium-high heat and add the vegetable oil along with 1 tablespoon of butter. Once the butter has melted and the fat begins to shimmer, carefully lay the dredged cube steaks in the pan without overcrowding. Sear for 2 to 3 minutes per side until a deep golden-brown crust forms. Transfer the browned steaks to a plate and set aside.
04 - Reduce the heat to medium. Add the remaining 1 tablespoon of butter to the same skillet along with the sliced onions and mushrooms. Cook, stirring occasionally, for 6 to 8 minutes until the onions are softened and translucent and the mushrooms have released their moisture and turned golden brown.
05 - Add the minced garlic and the reserved 2 tablespoons of seasoned flour to the skillet. Stir continuously for about 1 minute to cook off the raw garlic and flour taste, allowing the flour to lightly toast and coat the vegetables.
06 - Slowly pour in the beef broth and Worcestershire sauce, stirring constantly while scraping up all the caramelized browned bits from the bottom of the pan. Pour in the whole milk and stir to combine. Bring the mixture to a gentle simmer.
07 - Return the seared cube steaks to the skillet, nestling each one down into the bubbling gravy. Reduce the heat to low, cover the skillet with a tight-fitting lid, and let everything simmer gently for 20 minutes. The steaks should become fork-tender and the gravy should thicken to a silky, coating consistency.
08 - Remove the lid and taste the gravy, adjusting the salt and pepper if needed. Transfer each steak to a plate, spooning generous amounts of the onion-mushroom gravy over the top. Garnish with freshly chopped parsley and serve immediately alongside mashed potatoes, steamed rice, or buttered egg noodles.