Sorry just re-read your question. You need to get the number of posts with a difficulty of Easy, Average & Difficult for each term right?
You’ll need a custom wp_query with a tax_query and a meta_query.. Something like the below will get you the post count for Easy Chocolate Deserts..
$args = array(
'post_type' => 'recipes',
'tax_query' => array(
array(
'taxonomy' => 'desserts',
'field' => 'slug',
'terms' => 'chocolate',
),
),
'meta_query' => array(
array(
'key' => 'difficulty',
'value' => 'Easy',
'compare' => 'IN',
),
),
);
$easy_choc_query = new WP_Query( $args );
echo $easy_choc_query->found_posts;
More info from the Codex
To make it more dynamic we’d need to see your html structure. You’d possibly need to put something like the above inside the get_terms foreach loop, swapping out ‘chocolate’ and ‘easy’ for variables that changed with each iteration.
