  We present a pixelized source reconstruction method applied on Integral Field
Spectroscopic (IFS) observations of gravitationally lensed galaxies. We
demonstrate the effectiveness of this method in a case study on the clumpy
morphology of a $z \sim 2$ lensed galaxy behind a group-scale lens. We use a
Bayesian forward source modelling approach to reconstruct the surface
brightness distribution of the source galaxy on a uniformly pixelized grid
while accounting for the image point spread function (PSF). The pixelated
approach is sensitive to clump sizes down to 100 pc and resolves smaller clump
sizes with an improvement in the signal to noise ratio (SNR) by almost a factor
of ten compared with more traditional ray-tracing approaches.
