Hi

You can try this code

XML:

<?xml version="1.0" encoding="UTF-8"?>

<templates xml:space="preserve">

<t t-name="your_module_name.custom_template_tag_name">

<t t-set="value" t-value="your_python_method()"/>

        <t t-esc="value"/>

    </t>

</templates>

Hope it helps