點解燒蕃薯比蒸的好吃呢?

the reason is CONDENSED SUGAR :)
when broiled, sweet potato becomes sweeter, and the special aroma
from burned carbo, make it even tastier.

Steamed one, the SUGAR is not Condensed ... so it taste normal
and the starch is expanded so it soak up some sugar too.

Boiled one, the less tasty, since water dilluted the sweetness ...
that is why we put so much sugar in sweet soup ...

alien