Conditional menu items based on User Role - php

Question

I'm getting stuck on something that should be simple.
Using Laravel 5.3. I have a function setup for User::isAdmin() that can both check if a user has a given role.
I have some conditional menu items that should only appear for admins. how can I check for a role within a blade view file?
I have my many-to-many relationship setup and working fine for Users and Roles. When I try something along the lines of auth()->user()->isAdmin() or Auth::user()->isAdmin(), I get the following error:
Call to undefined method Illuminate\Auth\GenericUser::isAdmin()
Here's a copy of my User model:
<?php
namespace App;
use Illuminate\Foundation\Auth\User as Authenticatable;
use App\Role;
class User extends Authenticatable
{
// use SoftDeletes;
protected $table = 'users';
/**
* The attributes that are mass assignable.
*
* #var array
*/
protected $fillable = [
'first_name', 'last_name', 'company', 'email', 'tax_id', 'address', 'city', 'state', 'zip', 'phone','password',
];
/**
* The attributes that should be hidden for arrays.
*
* #var array
*/
protected $hidden = [
'password', 'remember_token',
];
public function roles()
{
return $this->belongsToMany('App\Role');
}
/**
* Find specified user role by id or name
* #param [type] $uid user_id
* #param [type] $role either name or id
* #return boolean [description]
*/
static function hasRole($uid, $role){
$user = User::find($uid);
if(is_numeric($role)){
foreach ($user->roles as $r) {
// var_dump($r->id);
if($r->id == $role){
return true;
}
return false;
}
}else{
foreach ($user->roles as $r) {
if($r->name == $role){
return true;
}
return false;
}
}
}
public function isAdmin(){
$user = User::find(Auth::user()->id);
foreach ($user->roles as $r) {
if($r->id == 1){
return true;
}
return false;
}
}
}