We know that \( \tan(\theta + n\pi) = \tan(\theta) \), where \( n \) is an integer. First, simplify the argument of the tangent:
\[
-\frac{23}{3} \pi = -8\pi - \frac{\pi}{3}.
\]
Since \( \tan(\theta + \pi) = -\tan(\theta) \), this becomes:
\[
\tan\left(-8\pi - \frac{\pi}{3}\right) = \tan\left(\frac{\pi}{3}\right) = \sqrt{3}.
\]