\documentclass[a4paper]{article}

\usepackage{pgfplots}

\begin{document}

\begin{tikzpicture}
\begin{axis}[
    x={(0.894cm,-0.447cm)},
    y=1cm,
    z=0cm,
    axis on top,
    scale mode=scale uniformly,
    ]
    \addplot3[surf,shader=interp] {x*y};
\end{axis}

\end{tikzpicture}
\end{document}

