Tomato pomace (TP) is an underutilized source of bioactive compounds with potential application in the food sector. A factorial experiment was designed to compare three culinary techniques, Thermomix®, Roner®, and traditional pan-frying, for the preparation of tomato sauces, enriched or not with TP, applying two temperatures and two cooking times. A multivariate analysis was performed on all the results obtained for the metabolites. The addition of TP significantly increased the content of bioactive compounds, especially phenolic compounds. OPLS-DA models were generated using cooking technique, temperature, and time as discriminant factors. The cooking technique had a greater effect on the phenolic content than cooking temperature or time. Thermomix® released bioactive compounds from the tomato into the sauce to a similar extent as pan-frying. Roner® proved to be effective in preserving the volatile fraction of the sauce. The Thermomix® significantly increased the amount of bioactive compounds, while the Roner® increased the volatile compounds.