Season the hake with salt and black pepper. Heat a large frying pan, approximately 30cm, and add 2 tablespoons of rapeseed oil. Place the hake, flesh side down, in the pan and cook for 4 minutes on each side. Remove and keep warm.
Add a little more oil to the pan and fry the cooked potatoes, onion and garlic for 3-4 minutes. Then add in the courgettes, black olives, tomatoes and thyme leaves and cook for anotherr 2-3 minutes. Season with salt, black pepper and lemon juice.