Picking the right inductor
The inductance of a switch mode power inductor is commonly specified at 100KHz and with a tolerance of around 20%. From what I have seen, the deviation due to frequency up to 100MHz or so is small enough that with the design just taking account of the 20% or so tolerance is good enough.

Some inductor datasheets may give a graph of inductance vs frequency, or impedance vs frequency. That can confirm the validity of the above assumption.

By the way, the specification of 100KHz is based on a sine wave. So whether the switching frequency is 100KHz or 1MHz, the switching waveform contains harmonics with multiples of the base frequency. Therefore you can never operate an inductor in a typical switch mode design at exactly just a particular frequency (sine wave) anyway.