Wp_query example for meta query with multiple meta field.

wp-query-with-meta-query.php

<?php
$args = array(
		'post_type' => 'product',
		'post_status' => 'publish',
		'posts_per_page' => -1,
		/*'meta_key' => 'ingredients',
		'meta_value' => ' ',
		'meta_compare' => '!='*/
		'meta_query' => array(
			'relation'    => 'AND',
			array(
				'key'     => 'ingredients',
				'value'   => ' ',
				'compare' => '!='
			),
			array(
				'key'     => 'custom_product_type',
				'value'   => 'recipe',
				'compare' => '='
			)
		)
	);
	
	$the_query = new WP_Query( $args );
	$count = $the_query->post_count;

	if ( $the_query->have_posts() ) :
		while ( $the_query->have_posts() ) : $the_query->the_post();
			$the_query->the_post();
			echo '<li>' . get_the_title() . '</li>'; 
		endwhile;
	endif;
?>