An electromagnetic cooking device comprising: an enclosed cavity (20, 222); a plurality of RF feeds (26A-26D, 226A-226B) configured to introduce electromagnetic radiation into the enclosed cavity (20, 222) to heat up and prepare a food load, the plurality of RF feeds (26A-26D, 226A-226B) configured to allow measurement of forward and backward power at the plurality of RF feeds (26A-26D, 226A-226B); and a controller configured to: select a heating target corresponding to an amount of energy that is to be delivered to the food load positioned in the enclosed cavity (20, 222); generate a heating strategy based on the heating target to determine a sequence of desired heating patterns, the heating strategy having a selected sequence of resonant modes for energy transfer into the enclosed cavity (20, 222) that corresponds to the sequence of desired heating patterns; cause the RF feeds (26A-26D, 226A-226B) to output a radio frequency signal of a selected frequency, a selected phase value and a selected power level to thereby excite the enclosed cavity (20, 222) with a selected set of phase shifts for a set of frequencies corresponding to each resonant mode of the selected sequence of resonant modes to create heating patterns; monitor the created heating patterns based on the forward and backward power measurements at the RF feeds (26A-26D, 226A-226B) to measure resonances in the enclosed cavity (20, 222) using spectromodal identification and storing a map of efficiency in frequency and phase domains in which the controller identifies resonant modes and Q-factors associated with each of the identified resonant modes; continue to monitor the created heating patterns and store maps of efficiency in the frequency and phase domains until a specified change is detected in at least one Q-factor; and when the specified change in the at least one Q-factor is identified, stop cooking the food load using the generated heating strategy. an enclosed cavity (20, 222); a plurality of RF feeds (26A-26D, 226A-226B) configured to introduce electromagnetic radiation into the enclosed cavity (20, 222) to heat up and prepare a food load, the plurality of RF feeds (26A-26D, 226A-226B) configured to allow measurement of forward and backward power at the plurality of RF feeds (26A-26D, 226A-226B); and a controller configured to: select a heating target corresponding to an amount of energy that is to be delivered to the food load positioned in the enclosed cavity (20, 222); generate a heating strategy based on the heating target to determine a sequence of desired heating patterns, the heating strategy having a selected sequence of resonant modes for energy transfer into the enclosed cavity (20, 222) that corresponds to the sequence of desired heating patterns; cause the RF feeds (26A-26D, 226A-226B) to output a radio frequency signal of a selected frequency, a selected phase value and a selected power level to thereby excite the enclosed cavity (20, 222) with a selected set of phase shifts for a set of frequencies corresponding to each resonant mode of the selected sequence of resonant modes to create heating patterns; monitor the created heating patterns based on the forward and backward power measurements at the RF feeds (26A-26D, 226A-226B) to measure resonances in the enclosed cavity (20, 222) using spectromodal identification and storing a map of efficiency in frequency and phase domains in which the controller identifies resonant modes and Q-factors associated with each of the identified resonant modes; continue to monitor the created heating patterns and store maps of efficiency in the frequency and phase domains until a specified change is detected in at least one Q-factor; and when the specified change in the at least one Q-factor is identified, stop cooking the food load using the generated heating strategy. select a heating target corresponding to an amount of energy that is to be delivered to the food load positioned in the enclosed cavity (20, 222); generate a heating strategy based on the heating target to determine a sequence of desired heating patterns, the heating strategy having a selected sequence of resonant modes for energy transfer into the enclosed cavity (20, 222) that corresponds to the sequence of desired heating patterns; cause the RF feeds (26A-26D, 226A-226B) to output a radio frequency signal of a selected frequency, a selected phase value and a selected power level to thereby excite the enclosed cavity (20, 222) with a selected set of phase shifts for a set of frequencies corresponding to each resonant mode of the selected sequence of resonant modes to create heating patterns; monitor the created heating patterns based on the forward and backward power measurements at the RF feeds (26A-26D, 226A-226B) to measure resonances in the enclosed cavity (20, 222) using spectromodal identification and storing a map of efficiency in frequency and phase domains in which the controller identifies resonant modes and Q-factors associated with each of the identified resonant modes; continue to monitor the created heating patterns and store maps of efficiency in the frequency and phase domains until a specified change is detected in at least one Q-factor; and when the specified change in the at least one Q-factor is identified, stop cooking the food load using the generated heating strategy.