Consulta:
SELECT A.recipe_name, GROUP_CONCAT(ingredient_name) AS ingredient_names
FROM recipes A
LEFT JOIN recipe_ingredients B ON A.id = B.recipe_id
LEFT JOIN ingredients C ON B.ingredient_id = C.iid
LEFT JOIN recipe_categories D ON A.id = D.recipe_id
LEFT JOIN categories E ON D.category_id = E.cid
WHERE category_id = <serach_id>
GROUP BY id
Resultado:
+-------------------+-------------------------------------------------+
| recipe_name | ingredient_names |
+-------------------+-------------------------------------------------+
| black forest cake | chocolate,baking powder,self-raising flour,milk |
| angel cake | self-raising flour,milk,chocolate |
| melting moments | milk,plain flour |
| croquembouche | self-raising flour,plain flour |
| crepes suzette | milk |
+-------------------+-------------------------------------------------+
Esto es lo que pediste usando GROUP_CONCAT. Cada ingrediente está separado por ,
