In a bowl mix all the dry ingredients: chickpea flour, cornstarch, salt, baking powder and baking soda.
Add warm water and olive oil and mix well, you will have a sticky batter.
Cover with film and let it rest into the fridge for half an hour.
Preheat the oven 356º Fahrenheit (180º Celsius).
Shape the grissini, dust with olive oil and add the seeds you like.
Bake for 10-15 minutes until the grissini are golden and crunchy.
Let them cool and serve.