The TREC recipe in a nutshell: a) a weakly lossy diffusive environment (e.g., a reverberation chamber), b) a single source, with no special features and c) a scanning system for sampling Green's functions over a surface. Fig. 1 : The robot optimized to weakly perturbate a reverberation chamber in the GHz range. On the right, a detail showing the electro-optic probe. First automated validation. Goals: a) to assess how strongly the generated wavefronts contrast with the diffusive background, b) they reproductibility and c) their ability to generate spatially resolved EM stress.