Place the pork slices on a cutting board, cover with plastic wrap, and lightly pound with a meat mallet or the bottom of a small pan until about 1/4 inch thick.

Season both sides of the pork evenly with 3/4 tsp salt and the black pepper. Set aside to rest for 15–20 minutes while you prepare the batter.

In a medium bowl, whisk the eggs until smooth. Add the mayonnaise and whisk until fully combined.

Add the flour and baking powder to the egg mixture and whisk until no lumps remain. The batter should be slightly thick but pourable.

Stir in the grated onion, remaining 1/2 tsp salt, and Dijon mustard and herbs if using. If the batter seems very thick, whisk in 1–2 tablespoons of water or milk until it coats a spoon in a thin layer.

Pour enough oil into a large skillet to thinly coat the bottom and place over medium heat. Allow the oil to heat until a drop of batter sizzles on contact.

Working in batches, dip each piece of pork into the batter, letting excess drip off, then carefully lay it in the hot skillet.

Fry the cutlets for 4–5 minutes on the first side, until the bottom is golden and the edges look set.

Flip each cutlet and cook for another 3–4 minutes, or until the second side is golden and the pork is cooked through but still juicy.

Transfer cooked cutlets to a plate lined with paper towels to drain. Repeat with remaining pork, adding more oil to the pan as needed and adjusting the heat so the batter browns without burning.

Serve hot with mashed potatoes, buckwheat, or a simple cucumber salad.