A sirloin tip steak is a lean, boneless cut from the sirloin primal, near the animal's rear, known for its robust beef flavor but less tenderness than other sirloin cuts due to its use in movement. It's often cut into cubes for kebabs or stew, but when sliced thinly or marinated well, it can be grilled or pan-fried, making it a flavorful and budget-friendly steak option, often found at supermarkets as steak tips or knuckle steak.