piece de resistance

noun, plural pièces de ré·sis·tance [pyes duh rey-zee-stahns; English pee-es duh ri-zee-stahns] /pyɛs də reɪ ziˈstɑ̃s; English piˈɛs də rɪ ziˈstɑns/. French.

1. the principal dish of a meal.
2. the most noteworthy or prized feature, aspect, event, article, etc., of a series or group; special item or attraction.

noun

1. the principal or most outstanding item in a series or creative artist’s work
2. the main dish of a meal

n.1831, from French pièce de résistance, originally “the most substantial dish in a meal.” Lit. “piece of resistance;” there seems to be disagreement as to the exact signification.