Start with the béchamel sauce. Pour 100 ml of milk into a separate bowl and mix it with the flour. Heat the remaining milk in a saucepan, add the butter and salt, and stir well. Once the mixture boils, pour in the milk-flour mix and stir vigorously until it thickens. Then add the grated Parmesan, a generous amount of grated nutmeg, and both white and black pepper. Remove from the heat and stir well until smooth. Cover with cling wrap, place it directly onto the surface of the sauce to prevent a skin from forming. Let cool slightly.
Finely chop the onion and garlic, and sauté in olive oil. Slice the zucchini lengthwise into thin strips and blanch them in boiling salted water for just one minute. Remove and lay out on a plate to cool. If using artichokes, simply chop them finely.
Boil the dry lasagna sheets in hot water for 3–4 minutes and lay them on a clean kitchen towel. They should soften but not be fully cooked.
Now assemble the lasagna. Spread a tablespoon of béchamel on the bottom of the dish and smooth it out well. Add a layer of lasagna sheets, spread with béchamel, then a layer of zucchini (and artichokes), sprinkle with the sautéed onion and garlic, then spoon on the ricotta (or bryndza), sprinkle with grated mozzarella, thyme, oregano, and a little salt. Repeat layers of pasta, béchamel, vegetables, cheese, and herbs until all ingredients are used. Top layer: mozzarella, thyme, and oregano.
Bake the lasagna for 25 minutes at 200°C.
Serve immediately with a green salad.