Often I just want to use content-assist (Ctrl+Space) to supply the import statement. However the exact-match proposal for a type can be buried within the proposal list:

In my case, the matching item is below the scroll belt, so it is difficult to navigate to quickly. Due to dynamic nature of Groovy, an unresolved type is just seen as a variable expression, so Organize Imports (Ctrl+Shift+O) does not always offer an answer.