The origin of the highest mass stars is still an enigma in modern astrophysics. Only massive clumps, at the onset of star formation, can reveal the initial conditions and shed light on the necessary physical processes leading to their formation. High angular resolution observations with ALMA of the immediate vicinity of a young high-mass protostar reveals chemical signatures for shocks associated with the mass accretion process. These shocks have high CH3OH abundance, and are rich in complex organic molecules. This suggests a different chemical composition for the immediate vicinity of a high-mass protostar compared to the low-mass hot-corino type objects. I will discuss the chemical differentiation of our targeted high-mass protostar and put our results in context with the typical molecular composition observed towards high-mass hot-cores, and low-mass hot-corino type sources.