Check the cod fillet for bones and remove any using the tip of a knife or a V-cut. Season generously with salt and pepper on both sides.
Wash the vegetables. Cut the zucchini into thin slices, cut the bell pepper into small strips, and cut each tomato in half, core it, then cut into thin strips.
Lightly grease a casserole dish.
Heat 3 tablespoons olive oil in a large pan over medium-high heat. Add the minced garlic clove, rosemary sprig, and dried thyme. Add the zucchini slices and bell pepper strips, and fry for 5 minutes, stirring occasionally, until softened. Season with salt and pepper.
Spread roughly half of the cooked vegetables on the bottom of the casserole dish. Layer some of the tomato strips on top.
Place the cod fillet on top of the vegetables.
Top the fillet with the remaining vegetables and tomato strips. Sprinkle 80 g freshly grated parmesan cheese evenly over the top.
Bake in a preheated oven at 180°C (350°F) using both top and bottom heat for 20 minutes, until the fish is opaque and cooked through.
Serve with fried potatoes or saffron rice and a side of crunchy salad.