Pre-heat oven to 350° F. Butter a square baking dish.
Heat oil in a non-stick frying pan. Fry bread in batches, about 1-2 minutes each side until golden brown. Add extra oil as needed. Remove from heat.
Arrange bread in layers in buttered baking dish.
Place milk in saucepan and bring to boil. Lower heat. Add ground saffron and cardamom, and let it simmer for 10 minutes. Occasionally stir and remove any milk residue with a wooden spoon. Remove from heat.
While the milk simmers on low heat, beat eggs and sugar with a whisk in a large bowl until well-mixed.
Pour milk into the egg and sugar mixture, and beat again until well-mixed.
Pour custard over bread, and bake uncovered for 25 minutes.
Top with crushed pistachios.