### Clue: He split, leaving Humphrey to get mashed potato (6)
### Answer: MURPHY 
 ### Explanation: Definition: potato
  **Anagram of**(mashed) UMPHRY("Humphrey" **minus**(….leaving) ("h" and "e")("he" split, ie. not subtracting "he" as a single word, but the individual letters)].
Answer:  The Irish or white potato.