Pour ¼ inch of neutral oil into a large skillet and warm over medium heat until it reaches 350°F on a thermometer, shimmering gently around a wooden spoon.
In a bowl, whisk buttermilk and eggs until blended; immerse each cube steak in the mixture for 10 minutes to tenderize and infuse tangy flavor.
Place seasoned flour mixture on a plate; coat each steak twice, pressing lightly so the flour adheres evenly for an extra-crispy crust.
Gently lower the coated steaks into the hot oil; fry 3–4 minutes per side until golden brown and crispy, adjusting heat to maintain a steady sizzle.
Carefully drain excess oil, leaving 2 tablespoons of flavorful drippings and browned bits in the skillet for depth and rich flavor.
Sprinkle 3 tablespoons of flour into the skillet; cook over medium heat, whisking constantly until the mixture turns light golden, about 1–2 minutes.
Gradually pour in cold whole milk while whisking vigorously; simmer until the gravy thickens into a creamy consistency, about 3–5 minutes.
Stir in salt and plenty of black pepper to taste; continue to cook 1 minute more and adjust seasoning as needed.
