How to modify page title?

You can set title using below code:

<referenceBlock name="page.main.title">
    <action method="setPageTitle">
        <argument translate="true" name="title" xsi:type="string">My Dashboard</argument>
    </action>
</referenceBlock>

If you want to change customer login create a file name with customer_account_login.xml add below code:

<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="1column" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
    <body>

            <!-- and for the page title: -->
            <referenceBlock name="page.main.title">
               <action method="setPageTitle">
                  <argument translate="true" name="title" xsi:type="string">Recipe</argument>
               </action>
            </referenceBlock>

    </body>
</page>

Put this function in Block page of that Module

public function _prepareLayout()  
{  

   $this->pageConfig->getTitle()->set(__('Your Page Title'));  

   return parent::_prepareLayout();  
}