Mathcamp Spelling Puzzle
Answer: CUT THE MUSTARD

Solve as described: find the unique 7-letter word that begins with the central letter and uses each letter exactly once:

Spelling beeAnswerMissing letter
L OE_CDTLOCATEDA
K _IGMONKINGDOMD
* EACDILMEDICALM
H YIO_STHISTORYR
_ OCIYETSOCIETYS
C REYNU_CENTURYT
V O_SIARVARIOUSU

The missing letters form one more spelling bee puzzle (with the central letter given by the asterisked missing letter), M ADRSTU; unscrambling this gives MUSTARD, and completing the given phrase "??? THE MUSTARD" gives the final answer, CUT THE MUSTARD.