<mat-list role="list">
  <mat-list-item *ngFor="let item of items">{{item}}:

    <mat-form-field>
      <input matInput>
    </mat-form-field>
    <button mat-stroked-button (click)="addCookie()">Add Cookie</button>

  </mat-list-item>
</mat-list>

export class ListOverviewExample {
  items = ['item 1', 'item 2', 'item 3'];

  addCookie() {
    console.log("here I would like to paste the value of the input field");
  }
}