My favourite part about the Evita Museum is the cafe & restaurant at the back of it, suitable both for a quiet drink or long and extremely satisfying lunch. It's a bit pricier but the setting more than makes up for it.
As one of the most famous faces of Argentina, you might be interested in delving into the life and history of Eva Peron. If not, the cafe/restaurant makes a perfect retreat from the tourist trail and it's somewhere to treat yourself after walking around all day.
Book ahead or go outside of usual Argie eating hours (lunch is normally 2-4pm and dinner 9-12pm here).