To a large mixing bowl, add all the ingredients for the scramble apart from the aquafaba, plant-based milk and olive oil. Using a potato masher or fork begin to mash together all the ingredients till they're all well coated with spice and seasonings. Give the chickpeas a quick taste an adjust flavour as desired. You may require more salt or onion etc.
Once you are happy with the flavour, to the bowl, add the aquafaba and plant-based milk and stir till well combined.
Heat a large cast-iron skillet on medium-high heat for 1 minute before adding the olive oil and tilting the pan till completely coated with oil.
Pour the mixture onto the pan and evenly distribute across the pan and pat using the back of a spoon to flatten it all out. Reduce heat to medium and let it cook for 3 minutes before using a spatula to scrape the sides of the pan to ensure nothing sticks or gets let behind.
Using the spatulata, lightly pat and push the mixture around, leaving no holes but allowing for new mixture to touch the base of the skillet to crisp up.
After 2-4 minutes, cut the skillet into a cross and begin flipping each side around onto it's uncooked side. Cook for 5-7 minutes before removing from heat.
Assemble your sandwich as you would (I recommend toasting the bread) and add desired amount of chickpea scramble to the mix.
Scramble will last up to 1 week in a tightly-sealed container in the fridge.