Eclipse IDE view gone - how to get it back

two option:

window -> New Window         //Opens with no editors, but preserves views layout
window -> reset perspective  //Keep editors, but resets layout view

If i understood your description correctly - you'll get what you want.

I managed to return my gone view without resetting the perspective!
I opened workspace/.metadata/.plugins/org.eclipse.e4.workbench/workbench.xmi, searched for "outline" there (the view was Outline) and found it (precisely org.eclipse.ui.views.ContentOutline) inside a children tag which had an attribute visible="false". I removed that attribute and also <tags>Minimized</tags> inside the children tag, saved the file, started Eclipse, and that was it, my view returned!