Chicken Paillards with Blood Orange Pan Sauce

Grate 1/2 teaspoon zest from 1 orange. Juice the orange into a medium bowl and add the zest. Segment the remaining 3 oranges (see Tip): Using a sharp knife, slice both ends off and remove the peel and white pith. Set a fine-mesh sieve over the bowl. Working over the sieve, cut the orange segments from their surrounding membranes. Squeeze juice out of the membranes and peel before discarding. Reserve the orange sections and juice separately.

Cut chicken into 4 pieces. Place between sheets of plastic wrap and pound with a meat mallet or heavy skillet until about 1/4 inch thick. Season with salt and white pepper.

Beat egg in a shallow dish. Place Parmesan on a plate. Dip the chicken into the egg, then dredge lightly in the Parmesan, pressing to help it adhere.

Heat oil and 1 tablespoon butter in a large nonstick or cast-iron skillet over medium-high heat. Add the chicken and cook, flipping once, until golden and an instant-read thermometer inserted in the thickest part registers 165 degrees F, 5 to 7 minutes total. Remove to a plate. Add the reserved orange juice to the pan and bring to a boil. Cook for 1 minute. Add the reserved orange segments and the remaining 1 tablespoon butter and stir until melted. Serve the chicken with the sauce and parsley, if using.