For numerical simulation purposes, the three dimensional menu box geometry (Fig. 3A) was mapped into tetrahedral elements using an inbuilt meshing option available in COMSOL Multiphysics®. The discretization was composed such that the regions of interest (food items) had finer meshes when compared to other regions of the geometry. Series of simulations with different mesh sizes were tried and the mesh size range was finalized based on two aspects: 1. Temperature history predicted by a chosen mesh should be as accurate (less than 1% deviation) as the temperature history predicted by the finest mesh possible, and 2. less computational time. Based on these two factors, to accommodate the complexity of the entire geometry, distance between proximate nodes was optimized and set in the range of 4.95 mm to 49.5 mm. The mesh size was relaxed (made coarse) only for the purpose of reducing computational time without significantly sacrificing the accuracy (< 1%) of the results.