A cooking method of providing food with stewed taste includes providing a liquid preparation comprising oil, sodium chloride, and emulsifier； placing the liquid preparation and food ingredients in a cooking container； and heating the liquid preparation and the food ingredients in the cooking container at a temperature of 80° C. or higher. The mass ratio of the emulsifier to the oil in the liquid preparation is at least 1:1000. The liquid preparation has a pH of from 4.0 to 7.0, a Brix value of from 1 to 15, an oil concentration of from 0.1 to 4 mass %, an emulsifier concentration of 1 mass % or less, and a static viscosity of from 5 to 100 mPa·s·g/cm3 when heated at 80° C.
