1. On cutting board, with sharp knife held in slanting position, almost parallel to cutting surface, cut tenderloin crosswise into 1/4 inch-thick slices. With meat mallet or dull edge of French knife, pound each slice to about 1/8 inch thickness.
2. In pie plate with fork, beat eggs. On waxed paper, mix flour and 1/2 teaspoon salt. Dip tenderloin pieces in egg, then in flour mixture to coat.
3. In 12-inch skillet over medium-high heat, heat butter or margarine and salad oil until hot. Add tenderloin pieces, a few at a time, and cook until lightly browned on both sides, about 3 to 4 minutes, removing pieces to plate as they brown.
4. Into drippings in skillet, stir water, sherry, pepper, and 1/4 teaspoon salt, stirring to loosen brown bits from bottom of skillet; return tenderloin pieces to skillet. Over medium-high heat, heat to boiling; cook about 2 minutes to blend flavors, stirring occasionally. Spoon tenderloin pieces with sauce onto warm platter; sprinkle with parsley.