Mix first 9 ingredients in medium bowl to blend well. Cover and refrigerate at least 1 hour and up to 1 day.
For each patty, shape 1/4 cup mixture into 3/4-inch-thick round. Heat heavy large nonstick skillet over medium-high heat. Add patties to skillet and cook to desired doneness, about 3 minutes per side for medium-rare.
To serve, prepare couscous according to package directions, mound in center of platter and surround with the beef patties.