Preheat oven to 180°C fan-forced.
Grease and line a 30 x 20 x 6cm lamington pan.
Grate zucchini into a sieve positioned over a bowl. Scatter with salt and leave for 15 minutes or so to drain, turning it over a couple of times and pressing down with your hands gently to get rid of some excess moisture.
Add leek and chorizo to a non-stick pan and cook over medium-high heat for 5 minutes or until cooked, set aside to cool.
Beat free-range eggs in a large bowl.
Add flour and beat until smooth. Add prepared zucchini, carrot, leek, chorizo, cheeses and oil and stir to combine.
Pour into prepared pan and bake in oven for 40 minutes or until cooked through.