Nested array in object Angular 2+ ngrx

The api is returning an Nested Objects, what i want here is to go inside the nested array and fetch all the patato-child.

I also made all the actions, effects, reducers.

Json view:

{  
  "id":13,
  "patato":Patato
    "patato-child":[  
       {  
        "id":12,
        "name":"Adventure"
       },
       {  
        "id":18,
        "name":"Drama"
       }
     ],
   "url":"randomUrl.jpg",
   "example":"Example"
}

Model view:

export interface Patato {
    id: number;
    patato: string;
    url: string;
    example: string;
    patato-child: PatatoChild[];
}

export interface PatatoChild {
    id: number;
    name: string;
}

Component.ts

  get patato-child() {
    return this.patato.patatoChild;
  } 

HTML view:

[object Object, object Object]

What's wrong with this structure, i cant get any patato-child with ngFor for listing all the patato child

I am using Angular 2+ Redux+@ngrx