Place pork between 2 layers of plastic wrap and pound to 1/4 inch thickness.
Combine mustard, sugar, cider vinegar, and crushed red pepper in a small bowl. And rub on both sides of the pork. Let sit for 15 minutes.
Heat a large skillet to medium high heat, and coat with cooking spray. Add pork and cook for 4 minutes on one side, turn over and spoon reserved mustard mixture over pork. ook for for 2 minutes or until done.
Add water, stirring slightly until thickened. Turn pork to coat and place on a serving platter. Pour juices over pork.