I have a bezier curve, and move along the curve

I have the tangent vector at some point on the curve.

tangent = coord_tangent[‘tangent’]

tangent.normalize()

then i align the object to the curve with the following

rotation = tangent.to_track_quat(‘X’, ‘Z’)

object.rotation_quaternion = rotation

… works fine this far …

tilt = … known

What i am looking for is how to apply an additional rotation to the object to account for the tilt of the curve at that point. I know the tilt angle is based on the tangent vector.