Benzaldehyde lyase (BAL) results in an efficient biocatalyst for the umpolung carboligation of furfural, HMF, and mixtures of them, leading to blended C₁₀–C₁₂ platform chemicals. Subsequently, the mixing and gentle heating (<100 °C) of the formed hydroxy-ketone with choline chloride leads to the formation of a novel biomass-derived deep-eutectic-solvent.