documentclass{article}

usepackage{tikz}

begin{document}
    tikzset{
        bloc/.style={
            anchor=south west,
            draw,
            minimum height=0.7cm,
            align=left,
            font=small
        },
    }



begin{tikzpicture}
pgfdeclarehorizontalshading{myshadingA}{3cm}{
    color(0cm)=(green);
    color(1.44cm)=(green);
    color(1.8cm)=(red)
}
node[bloc, minimum width=5.5cm,
      shading=myshadingA]
at (-9,0.5) {Initialize process};

end{tikzpicture}
end{document}