A gas turbine engine assembly comprises a casing defining a gas path, the casing including a shroud having an annular body having a surface defining a portion of gas path, the shroud having slots configured for receiving inserted vanes. The slots are delimited substantially about their perimeter by respective flanges, the flanges radially offset from the shroud gas path surface so as to be disposed outside of said gas path, the flanges defined by opposed flange surfaces. Vanes received in the slots. Grommets engage the vanes at the slots. Inserts extend between the shroud and the grommets, the inserts having slots configured for engaging both of the opposed flanges, the inserts extending in a radial direction from at least the respective flange to an adjacent said shroud gas path surface to substantially matchingly mate with an inner surface the adjacent shroud gas path surface.