Log burner finish?

Hi all I need to render a big surround for a log burner it consists of engineered bricks, lintels and concrete blocks! Not sure of the best method? Has to be done in sand cement and lime but needs a smooth finish
Do I scratch coat it and then top coat in sand and cement and key the top coat and then pva and skim with multi finish?
Any suggestions please


Some threads get lost when it gets busy so I have bumped this up :D