“Lagrangian” for a Non-Lagrangian Field Theory with $\mathcal{N}=2$ Supersymmetry

We suggest that at least some of the strongly coupled $\mathcal{N}=2$ quantum field theories in 4D can have a nonconformal $\mathcal{N}=1$ Lagrangian description flowing to them at low energies. In particular, we construct such a description for the $\mathcal{N}=2$ rank one superconformal field theory with $E_6$ flavor symmetry, for which a Lagrangian description was previously unavailable. We utilize this description to compute several supersymmetric partition functions.