The preparation of a traditional sauce based on amaranth leaves cooked palm nuts or red palm oil (RPO) in Benin was described. The recipes included an optional step of leaf blanching at 100 °C, heating the RPO or boiling the palm nuts and finally cooking all the ingredients together. The influence of this multi-step preparation on the carotenoid content of the final dish was measured. During blanching of amaranth leaves, violaxanthin was the only carotenoid to be significantly affected by the thermal treatment. Retinol activity equivalent (RAE) remained high after blanching even when alkaline traditional potash was added. Heating the RPO was the most critical step because it considerably and very rapidly (in <3 min) decreased α-carotene, β-carotene and RAE values (more than 70%). Sauces calling for palm nuts, RPO and amaranth leaves were equally advantageous in terms of final RAE value. These ingredients and sauces can thus be used in programmes to reduce vitamin A deficiency.