How can I get the post ID from a WP_Query loop?

get_the_ID() can (only) be used within the loop.

This retrieves the ID of the current post handled by the loop.

You can use it on it’s own if you need it only once:

$dish_meta = get_post_meta( get_the_ID(), 'dish_meta', true );

You can also store it as a variable if you need it more than once:

$post_id = get_the_ID();

$dish_meta = get_post_meta( $post_id, 'dish_meta', true );

$drink_meta = get_post_meta( $post_id, 'drink_meta', true );

print_r( $post_id );

//etc

Reference: get_the_ID()