In recent years, an exciting new type of engineering materials called high entropy alloys (HEAs) has received widespread attention. The excellent microstructural stability of these materials makes them interesting candidates for high temperature structural applications. A novel type of HEAs with eutectic microstructure, with good castability allowing easy production in bulk form, have shown an extraordinary combination of strength and ductility at temperatures ranging from cryogenic to 700°C. By the proposed experiments we aim to unravel the reason for this remarkable behaviour by employing in-situ neutron scattering experiments to understand the deformation mechanisms over the entire temperature regime.