Stewart recorded his debut album, Louis the First in Dublin, and then, subsequently in London, albums with Billy Higgins, Peter Ind, Sam Jones, Red Mitchell, and Spike Robinson. From the mid to late 1970s he worked George Shearing, touring America, Brazil, and major European festivals, and recording eight albums, including several in trio with Bassist Niels-Henning Orsted-Pedersen. He has appeared on albums by Joe Williams and J. J. Johnson.