Bertrand Grébaut, the French chef known for transforming traditional dining with his acclaimed Paris restaurant Septime, died on Thursday in Paris at the age of 44. His business partner, Théophile Pourriat, confirmed the death on Septime’s Instagram page, noting that Mr. Grébaut had been diagnosed with cancer in the fall of 2023 and had since reduced his professional activities.

Septime, which opened in 2011, quickly gained a reputation for blending haute cuisine techniques with a casual bistro atmosphere. Named after a fictional restaurateur from the 1966 film comedy "Le Grand Restaurant," the establishment was located in Paris’s 11th Arrondissement, a neighborhood considered unconventional for fine dining at the time. Mr. Grébaut and Mr. Pourriat sought to challenge the rigidity of France’s traditional restaurant scene, which had lagged behind trends like the farm-to-table movement emerging in the United States.

With its minimalist design featuring polished concrete floors and rough wooden tables, Septime offered a fresh and modern dining experience that diverged from the formal white-clothed establishments common in Paris. The restaurant earned a Michelin star in 2014, becoming increasingly difficult to book, a testament to Mr. Grébaut’s influence on contemporary French cuisine.

Born in Paris on December 5, 1981, to corporate executive Christian Grébaut and art historian Catherine Arteau-Grébaut, Bertrand Grébaut’s early interests included graffiti and graphic design. However, his passion for food, influenced by a family background in winemaking and a childhood filled with diverse home-cooked meals, ultimately led him to enroll at Ferrandi Paris culinary school. He honed his skills through challenging apprenticeships, including a formative period under Alain Passard at the three-Michelin-starred L’Arpège, where he developed a focus on vegetable-driven cuisine.

Before opening Septime, Mr. Grébaut served as head chef at L’Agapé, earning a Michelin star in 2009, and traveled extensively in Asia for inspiration alongside his partner, chef Tatiana Levha. Together with Mr. Pourriat, he expanded their ventures to include La Cave Septime, a natural wine bar; the seafood-focused Clamato; and the pastry shop Tapisserie, known for its distinct desserts. In 2018, they also launched D’une île, an inn housed in a restored 17th-century farmhouse in the Perche region.

Mr. Grébaut was known for eschewing the celebrity chef culture, avoiding social media and commercial licensing deals. He encouraged diners to focus on the shared experience of a meal rather than digital documentation.

He is survived by Tatiana Levha, their two children, Anna and Roman, and his mother. Ms. Levha and her sister Katia operate the Parisian bistros Le Servan and Double Dragon, which specialize in Asian cuisine. Mr. Pourriat stated that the group’s restaurants will remain open, suspending operations only briefly to allow for Mr. Grébaut’s funeral arrangements.