Start by preparing your tempeh: Cut into strips and pat dry with a clean towel. In a shallow dish, mix together the marinade, and add the tempeh strips. Coat all your strips well in the marinade and leave for at least 30 minutes.
Heat up a pan with olive oil and add the marinated tempeh strips. Cook for around 5-8 minutes each side on medium-high heat or until golden brown.
For the tzatziki, grate your cucumber and squeeze out some of the water. Add it to a bowl along with the rest of your ingredients and combine.
To assemble your gyros, start by toasting your pittas and chopping your cucumber, tomato and lettuce. Add lettuce, rocket, tomatoes and tempeh to the pitta bread. Top with a few teaspoons of tzatziki, some fresh coriander and a sprinkle of chili flakes.
You can serve them by rolling them up and wrapping them in some parchment paper and tying them together with a string if you wish. Enjoy!