For the dressing, saute the chicken livers until cooked through. In a blender, puree liver with oil, vinegar, and shallots. Season with salt and pepper to taste. Set aside. For the salad, saute the lardons in a medium saute pan over medium heat until crispy. Transfer with bacon fat into mixing bowl. Toss with frisee and enough dressing until coated lightly. Generously spread cheese on croutons. Serve salad in individual plates topped with 1 crouton.