Usage patterns
〈物〉が名物になるfor something to become a (region's) famous specialty
These hot-spring buns became the town's famous specialty.
名物として知られるto be known as a local specialty
This region is known for its crab dishes as a local specialty.
名物を食べるto eat a local specialty (dish)
When I travel, I like to eat the local specialty food.
Expressions
名物にうまいものなしfamous things rarely live up to their reputation; local specialties are often disappointing