Usa GROUP_CONCAT FUNCTION
http://dev.mysql.com/tech-resources /articles/4.1/grab-bag.html
SELEct m.meal_Id,
GROUP_CONCAT(dish_id) dish_ids,
GROUP_CONCAT(dish_name) dish_names
FROM DISH_HAS_DISHES m JOIN DISH d ON (m.dish_id = d.dish_id)
GROUP BY meal_Id