We demonstrate a way of producing monodisperse Al3(LiScZr) core/shell inclusions using solid-state reactions. A uniform distribution of particles with a Li- and Sc-rich core surrounded by Li-rich shell a few nanometers thick with Zr segregating at the core/shell interface can be made reproducibly by exploiting kinetic and thermodynamic parameters. This approach to generating precipitate distributions can be applied to a range of alloys and could lead to new types of dispersion-strengthened materials.