Preheat your oven to 200°F and set up a wire rack on a baking sheet.

In a shallow dish, combine 4 cups flour, 5 teaspoons salt, 1 teaspoon black pepper, and 1/8 teaspoon cayenne pepper.

In a separate dish, whisk together 2 beaten eggs, 1 teaspoon baking powder, 1/2 teaspoon baking soda, and 1 cup buttermilk until slightly foamy.

Pat each cube steak dry with paper towels.

Dredge each steak in the flour mixture, then dip into the buttermilk mixture, then back into the flour mixture again, creating a double coating.

Heat peanut oil to 375°F in a deep pan or Dutch oven, about 1 inch deep.

Fry each steak for 2½ minutes per side until deeply golden brown.

Drain briefly on paper towels before transferring to the warm oven while preparing the gravy.

For the gravy, strain the frying oil, reserving 2 tablespoons and the crispy bits.

Sauté the minced onion and garlic in the reserved oil until softened.

Whisk in 3 tablespoons flour until lightly browned, about 1-2 minutes.

Gradually add chicken broth while whisking constantly to prevent lumps.

Slowly pour in the whole milk, continuing to whisk.

Season with 1/2 teaspoon salt and 1/4 teaspoon pepper, then simmer until thickened to desired consistency.

Serve the steaks hot with gravy poured generously over the top.