If you want to read only one field value, I think, using the template reference variables is the easiest way
Template
<input #phone placeholder="phone number" />
<input type="button" value="Call" (click)="callPhone(phone.value)" />
**Component**
callPhone(phone): void
{
console.log(phone);
}
If you have a number of fields, using the reactive form one of the best ways.