Place all ingredients in a bowl and mix with your hands until combined.
Form the mixture into 4 burgers and fry in a little bit of butter on medium heat for around 10-12 minutes, filliping them every couple of minute, or until the burgers are no longer pink in the middle and the juices run clear.
Fry the shallot and garlic in a little bit of butter on low medium heat until fragrant and translucent. Add the mushrooms and cook for a few minutes until the mushrooms have reduced in size and softened. Add the spinach and cook for a couple of more minutes until the spinach have been cooked.
Place the mushrooms on a plate and place the chicken burgers on top.