1. If chicken breasts are more than 1/2 inch thick, put them between 2 sheets of plastic wrap and gently pound with flat side of a meat pounder or with a rolling pin until 1/2 inch thick.
2. Whisk together egg whites and 1/2 teaspoon salt in a shallow dish until whites are loosened but not foamy. Put sesame seeds in another shallow dish. Pat chicken dry and sprinkle with remaining 3/4 teaspoon salt. Dip chicken, 1 piece at a time, in egg whites, letting excess drip off, then dredge in sesame seeds. Transfer to a wax-paper-lined tray.
3. Heat oil in a 12-inch heavy skillet over moderately high heat until hot but not smoking. Reduce heat to moderate and cook 3 pieces of chicken, turning over once with tongs, until coating is golden and chicken is cooked through, 10 to 12 minutes, then transfer to a plate. Remove any browned sesame seeds from skillet, then cook remaining chicken.

Yield: 6 servings