Pat steaks dry and season lightly on both sides with granulated onion, granulated garlic, and salt and pepper to taste; set aside while you prep remaining ingredients.

Preheat oven to 200ºF with a lined baking sheet with a wire rack on the middle shelf. Place a wire rack on another baking sheet and set aside for the floured steaks.

Combine 2 cups flour, cayenne pepper, and salt and pepper to taste in a large shallow bowl.

Whisk egg, baking powder, and baking soda well and add to another large shallow bowl. Stir in buttermilk.

Drop the seasoned steaks into the flour mixture and turn to coat; shake off any excess, dip in the buttermilk mixture, and return to the flour mixture and turn to coat. Transfer to prepared baking sheet.

Place a wide Dutch oven over medium-high heat and pour cooking oil to a depth of 1½ inches. Heat to 375ºF (this is important to achieve a crisp crust). Working in batches, fry the steaks, turning once, until golden brown, about 6 minutes total; remove to rack in warm oven as they’re done. Return oil to temperature before frying another batch.

When all the steaks are fried, carefully drain the oil through a fine mesh strainer into a heatproof container. Return the browned bits to the Dutch oven over medium heat and add 3 tablespoons of the oil. Add mushrooms and onions and cook, stirring often, until onions are very soft, about 10 minutes. Add the garlic and thyme and cook 1 minute; add 3 tablespoons of flour (any leftover flour from flouring the steaks is fine) and cook, stirring constantly, until flour is browned. Slowly whisk in beef broth or water and cook, stirring, until thickened; season to taste with salt and pepper. To serve, put a scoop of rice or potatoes on each serving plate. Top with a steak and spoon gravy over the top; garnish with green onions. Pass any extra gravy at the table.