This seems to work:
x = linspace(0,1,1000);
y = linspace(0,1,1000);
[X,Y] = meshgrid(x,y);
Z = -X.^2 - Y.^2;
mesh(X,Y,Z+2)
box on
hold on
contourf(X,Y,Z+2)
zt = get(gca, 'ZTick');
set(gca, 'ZTick',zt, 'ZTickLabel',zt-2)
view([15 35])
Change the view arguments to the orientation you want.