The path from SBT to Scala-IDE is well described in many places:
What is the reverse for this? If I start a new project in Scala-IDE, can I just add a build.sbt file and somehow tell Eclipse to use this when running the application?
Apologies if this seems obvious to some, but I've recently moved from ItelliJ Idea to Scala-IDE and I'm not certain about setting up Scala-IDE to use SBT and my sbt config files.
No, you cannot do this. The way to do it is as you described. Then, whenever you make changes to build.sbt (e.g., new jar dependency), rerun the eclipse
command from sbt and refresh the project in Eclipse so that the newly generated files are reloaded.