Using Underscore.js help to iterate over it

So I managed to get my array grouped by Entity name using Underscore.js with _.groupBy. It gives me the next output:

The output its correct, the problem is that I cant *ngfor over it on my html because is obviously not an array. Do anybody know how to iterate over this and for example show on my html part a “mat-expansion-panel-header” with the output blue text?