We present a recipe for preparing nontoxic microemulsions using an unsaturated fatty acid ethyl ester as oil, a long-chain soy bean lecithin as amphiphile, and pentane-1,2-diol as cosolvent. The mixture permits the preparation of microemulsions at any prescribed temperature within the experimental window, with the mixture of the two amphiphilic compounds being rather efficient emulsifiers. Furthermore, the mixture turns out to be rather insensitive to NaCl brine concentrations up to 2 wt%.