I suspect you have more foods that are of category 'ORGANIC'. Otherwise there is no need for the table FOOD_CATEGORY. The table FOOD_CATEGORY is there to create a many-to-many relation.
So why not :
SELECT PRICE, LABEL
FROM FOOD
JOIN FOOD_CATEGORY ON (FOOD_CATEGORY.FOOD_ID = FOOD.FOOD_ID)
JOIN CATEGORY ON (CATEGORY.CATEGORY_ID = FOOD_CATEGORY.CATEGORY_ID)
WHERE CATEGORY.NAME = 'ORGANIC';
Or use IN instead of =
SELECT PRICE, LABEL
FROM FOOD
WHERE FOOD.FOOD_ID IN (
SELECT FOOD_ID
FROM FOOD_CATEGORY
WHERE FOOD_CATEGORY.CATEGORY_ID = (
SELECT CATEGORY_ID
FROM CATEGORY
WHERE NAME = 'ORGANIC'
)
);