Sandwich Coding Standards

What happen if the user don’t have capability to eat sandwich? WSOF?

If I’d want to follow average default themes templates, I’d go for

// eat-sandwich.php (as @Rarst said avoid wp-lunch.php as it's not part of WP core)

get_header( 'sandwich' );

if ( current_user_can( 'eat_sandwich' ) ) {

  get_template_part( 'eat-sandwich', 'content' );

} else { // user can't eat sandwich. An apple?

  $alternative = apply_filters( 'alternative_to_sandwich', 'apple' );

  if ( 'sandwich' == $alternative ) {
     // No sandwich allowed!
     $alternative="apple";
  }

  get_template_part( "eat-$alternative", 'content' );

}

get_footer( 'sandwich' );

And then

// eat-sandwich-content.php

$fillings = get_fillings_query(); // in functions.php

if ( $fillings->have_posts() ) : while ( $fillings->have_posts() ) :

   get_template_part( 'filling', get_filling_type() );

endwhile;

wp_reset_postdata();

else :

  _e( 'Sorry, no fillings found. Eating an apple may help to stop hunger.', 'txtdomain');

endif;