Prepare the Vegetable Base: Grate the potatoes, zucchini, and carrot into a large bowl. Add the ½ bell pepper, finely diced. Season with a generous pinch of salt, stir, and let the mixture sit for 10 minutes to draw out excess moisture.

Form the Base: After 10 minutes, squeeze the vegetable mixture in a clean kitchen towel to remove as much liquid as possible. Return the drained vegetables to the bowl. Add the two eggs, 70 g of flour, chopped parsley, and a pinch of black pepper. Mix everything until well combined.

Partially Bake the Base: Lightly grease a baking dish with vegetable oil. Press the vegetable mixture evenly into the bottom of the dish to form a crust. Place in a preheated oven at 180°C (360°F) and bake for 20 minutes to set the base.

Prepare the Chicken Filling: While the base is baking, heat a drizzle of olive oil in a skillet over medium-high heat. Add the chopped onion and cook until softened. Add the cubed chicken fillet and cook until browned on all sides. Season with salt, pepper, Provençal herbs, and a dash of turmeric. Add the diced tomato and cook for 2-3 minutes, until it softens slightly.

Prepare the Topping Sauce: In a separate small bowl, combine the kefir, mayonnaise, minced garlic, and chopped dill. Season with salt and pepper to taste.

Assemble the Bake: Remove the partially baked vegetable base from the oven. Spread the cooked chicken and vegetable filling evenly over the top of the base. Sprinkle the grated cheese generously over the filling.

Final Bake: Pour the kefir and mayonnaise sauce evenly over the entire dish. Return the casserole to the oven and bake for another 20 minutes at 180°C (360°F), or until the top is golden and the sauce is bubbling.

Serve: Let the bake rest for a few minutes before slicing and serving.