//TestReturningElement.php (app/models)

class TestReturningElement extends Eloquent {

    protected $table = 'test_returning_element';
    public $timestamps = false;

    // the primary key name
    public function getKeyName(){
        return "id3";
    }

    public static function insertAndGetElement()
    {
        $newElement = new TestReturningElement;
        $newElement->id1 = 5;
        $newElement->id2 = 5;
        $newElement->id3 = 6;
        $newElement->save();

        // those two lines give different results
        return $newElement;
        return TestReturningElement::find(6);
    }
};

//Database migration :

public function up()
{
    Schema::create('test_returning_element', function($table)
    {
        $table->integer('id1')->unsigned();
        $table->integer('id2')->unsigned();
        $table->integer('id3')->unsigned();

        $table->primary('id3');

    });
}

// TestController.php (app/controllers)

class TestController extends BaseController
{
    public function getTestCreation()
    {
        return TestReturningElement::insertAndGetElement();
    }
}

// routes.php

Route::controller('test', 'TestController');

// the result can be viewed on /test/test-creation