Yes, you can substitute butter with ghee in shortcrust pastry. Ghee adds a nutty flavor and can result in a flakier crust due to its lower moisture content.
Ghee is clarified butter, meaning the milk solids and water have been removed. This makes it nearly 100% fat, unlike butter which contains water. When making shortcrust pastry, the fat coats the flour particles, preventing gluten development and resulting in a tender, crumbly texture. Because ghee is pure fat, it can create a more tender and sometimes flakier crust than butter. The nutty flavor of ghee also adds a unique dimension to the pastry. To substitute, use the same amount of ghee as you would butter in your recipe. You may find that the dough is slightly drier, so add a tablespoon or two of ice water if needed to bring it together. The key is to keep all ingredients cold, regardless of whether you're using butter or ghee.
When using ghee, chill it thoroughly before incorporating it into the flour. This will prevent the ghee from melting too quickly and ensure a flaky, tender crust. You can even freeze the ghee in small cubes for 15-20 minutes before using.