How to cook
Clean and remove the seeds from all the vegetables. Peel the eggplants, cut them into slices and salt them. Cut the potatoes into round slices and arrange them at the bottom of an oven dish that you've smeared with olive oil.
Arrange the eggplants on top of the potatoes. Separately, chop the tomatoes and mix them with the peppers that you've baked and cut beforehand. Season with salt and black pepper to taste.
Pour the tomato mixture over the eggplants. Saute the onions and garlic with salt to taste. Add the chopped zucchini to them. This is the second to last layer of the moussaka - finish off with a layer of eggplants.
Cover the oven dish with foil and bake at 390°F (200 °C) for 40-45 min. While it's baking, you can prepare the topping.
Mix the milk with the flour until you get a homogeneous mixture and season with 1 tsp salt.
Once the moussaka is baked, pour the topping over it and bake for a final 15-20 min.