  We study the structure of single $\Lambda$-hypernuclei using the
Hartree--Fock--Bogoliubov method. Finite range Gogny-type forces are used to
describe the nucleon-nucleon and $\Lambda$-nucleon interactions. Three
different $\Lambda$-nucleon Gogny forces are built. The unknown parameters of
these forces are obtained by fitting the experimental binding energies of the
$1s$ $\Lambda$ single-particle state in various hypernuclei using the
``Simulated Annealing Method''. These forces are then used to calculate the
binding energies of the other ($1p, 1d, 1f, 1g$) $\Lambda$ single-particle
states in the different hypernuclei. The predicted values are found to be in
good agreement with the experimental data for the three forces constructed. In
addition, we calculate also the root-mean-square radii of ground state
$\Lambda$ orbital, as well as several global properties of the hypernuclei
considered such as their ground-state Hartree--Fock--Bogoliubov energy, their
pairing energy and their quadrupole moment.
