The breeding of local breeds with small or very small numbers of animals is currently attracting renewed interest because it is in line with agro-ecological issues and meets consumer aspirations. This article focuses on the Maraîchine cattle breed, which is currently used for meat production. Within the framework of a research-action project, researchers built a protocol with farmers to evaluate the nutritional and sensory quality of their beef. After presenting the context of the Maraîchine cow farm, the article presents the experimental design and the results obtained. Ten grass-finished beef cattle and 8 concentrate-finished beef cattle from 7 farms were recruited. The analyses were performed on flank steak and focused on the biochemical and metabolic characteristics of the muscle, sensory qualities and rheological properties, intramuscular lipid content and fatty acid composition, and finally, on the antioxidant potential of the meat. Meat is on average richer in polyunsaturated fatty acids and less rich in saturated fatty acids than other meat breeds. The grass finishing diet leads to leaner meats with a better health value. Antioxidant defenses are very high and grass-fed finishing mainly strengthens exogenous antioxidant defenses. Regarding sensory and rheological qualities, grass finishing does not affect the color of the meat but results in a less tender meat despite an increase in juiciness.