<select name="select" [(ngModel)]="selected" (change)="onChange($event)">
  <option [ngValue]="undefined" selected disabled hidden>
    {{ label }}
  </option>
  <option *ngFor="let kv of data | async" [ngValue]="kv.key">
    {{ kv.value }}
  </option>
</select>
<!-- <label for="select">{{ label }}</label> -->
