What does the cryptic crossword clue "Urge Tom after training to be a discerning diner (7)" mean?

The definition is "diner". The wordplay uses an anagram. anagram of URGE + TOM = GOURMET; definition: "diner" The answer is GOURMET.

Urge Tom after training to be a discerning diner (7)

Daily Mail Cryptic #16241 | 10 Across | 2020-01-31 flower