Trim fat from pork; cut pork into 1/2-inch strips, and place in a shallow dish. Combine lemon juice and next 4 ingredients, stirring well. Drizzle 3 tablespoons lemon juice mixture over pork. Cover and marinate in refrigerator 2 hours. Set remaining lemon juice mixture aside.
Add tahini and sugar to remaining lemon juice mixture; stir well, and set aside. Combine romaine lettuce, cabbage, and jicama in a bowl; toss, and set aside.
Remove pork from marinade, discarding marinade. Place pork in a large nonstick skillet, and cook over medium heat 5 to 7 minutes or until done.
To serve, place 2 cups lettuce mixture on each of 4 plates. Top evenly with pork strips. Drizzle lemon juice mixture evenly over salads. Serve with rice cakes.