Heat the oil in a wide pan. Add the gyros and fry vigorously on all sides, season with salt and pepper and cook for 8 minutes. Take it from the stove and let it cool off.
Pour the mushrooms into a sieve and drain very well. Clean and wash the spring onions and cut into thin rings.
In a large bowl, mix the tzaziki with the lemon and orange juice, season with salt and pepper. Put the gyros with the mushrooms and the spring onions in the bowl and mix well.