I'd recommend not adding baby food at all, CGD is just fine for them.
You usually only add baby food to it if a gecko is only used to eating baby food (to get them started eating cgd) and then you slowly wean it out of the mix.
Ratios I'd personally do:
1 part mix, 1 part water, 1 part baby food
or
1 part mix, 1 1/2 part water, 1/2 part baby food