Who doesn't like potatoes? Thanks to potatoes, we can make french fries! What else do we need? ;-) A potatoe is a round white vegetable with a brown, red, or pale yellow skin, that grows under the ground. You can have a roast, fried, boiled, mashed potato or even jacket potato! The latter is normally cooked in its skin. Yes, you put it in the boiling water. No peeling needed. However, a hot potato means that either you just boiled in in this water, or... you have in mind a topic to discuss, usually a controversial one. "Such a hot potato that it was dropped" <- ironically about a "controversial" topic of discussion.
Definition: a subject or an issue too difficult to discuss.
Example: this problem has become a hot potato.