Add all the batter ingredients - milk, chia seeds, cinnamon, vanilla extract, pinch of kala namak (if using) - to a high speed blender and whizz until smooth. Pour into a wide shallow container.
Place two slices of bread in the batter. After a few seconds, flip to coat the second side, making sure all areas of the bread are coated.
Heat ½TBSP vegan butter in a non-stick frying pan (skillet) on medium heat. Swirl the pan to ensure the bottom is covered entirely in butter, then place the two slices of bread in it. Cook for 3 minutes on each side, or until golden brown. To flip the bread, carefully loosen it first using a slotted turner to ensure all the lovely batter stays on the bread.
Transfer to a plate and place in the oven on low heat to keep it warm while you prepare the next two slices of bread. Coat the bottom of the pan in another ½ TBSP vegan butter and repeat the process as above.
Once the French Toast is ready, arrange on plates with your chosen toppings and serve.