What does the cryptic crossword clue "Where electoral system is cooked up and tested? (6)" mean?

The wordplay uses a charade (building blocks). PR (synonym="PR") + OVEN (synonym="OVEN") = PROVEN The answer is PROVEN.

Where electoral system is cooked up and tested? (6)

Independent Cryptic #12100 | 24 Across | 2025-07-21 flower