Epitaxial Fe/MgO/Fe tunneling junctions with nonmagnetic interlayers bewteen the MgO barrier and Fe electrods are interesting since Au/Ag interlayers create quantum wells in the minority-spin channel which may give rise to resonant tunneling. Because of a good match between Fe and Au/Ag majority-spin bands there are no quantum wells in the majority-spin channel. The idea is to engineer a junction with resonant tunneling in the minority-spin channel in the ferromagnetic(FM)configuration while tunneling in the antiferromagnetic (AF) configuration remains nonresonant. We investigated Fe/Au/MgO/Au/Fe junction with two Au interlayers. In the AF configuration all electrons see a single quantum well and no resonant tunneling occurs. However, in the FM configuration the minority-spin electrons see two quantum wells adjacent to the MgO barrier. A barrier sandwiched between two wells can give rise to resonant tunneling with 100\% transmission through the barrier. A resonant enhancement of TMR is thus expected.