How do I transition smoothly between two lerps/slerps?

How do I smoothly transition from one lerp/slerp to another while the first is still in progress? Currently the code just stops the object rotation before starting the second.

The code so far:

             if (rotating)
             {
                 rotationTime += Time.deltaTime * RotationSpeed;
 
                 myRigidBody.transform.rotation = Quaternion.Lerp(myRigidBody.transform.rotation, DesiredDirectionOfTravel, rotationTime);
             }
 
             if (rotationTime >= 1.0f)
             {
                 rotating = false;
             }