JERSEY CITY — One Monday afternoon in December, Nur-E Gulshan Rahman was perched on a hot-pink step stool, her body hunched over a boti, a steel cutting instrument she bought back in her native Bangladesh. Her face was inexplicably free of sweat as she sliced bulky calabazas into small diamonds.

A large knife might suffice for other cooks when it came to that task. But not for Ms. Gulshan, who prefers the boti, its blade shaped like a viper’s fang.

“Too hard,” she said when asked why she doesn’t use a chef’s knife. “We are not used to cutting pumpkin with the knife in Bangladesh.”

Ms. Gulshan, 61, is the chef and sole cook at Korai Kitchen, the Jersey City restaurant she opened last February with her youngest daughter, Nur-E Farhana Rahman, 31. Nur-E Farhana handles business operations and acts as the restaurant’s gregarious host. Together, they are the engine powering the city’s first Bangladeshi restaurant, housed in a former deli in Journal Square, just blocks from the thicket of Indian restaurants on Newark Avenue.