Wash and dry the zucchini, then cut them in half lengthwise and, using a potato peeler, cut very thin slices. Then cut the resulting slices into strips and collect them as you go in a colander. Season with a generous pinch of salt, stir and let them lose their water for about 20 minutes.
Meanwhile, prepare the saffron sauce: melt the butter in a small saucepan, add the cornstarch and stir quickly off the heat, then gradually incorporate the milk, flush to avoid lumps, and put back on low heat. Stir to thicken, then add salt, add saffron and stir with a hand whisk until completely dissolved. Turn off and keep aside.
Drain the zucchini, transfer to a clean bowl and season with a drizzle of oil and the finely chopped herbs. Stir.
Cook the ravioloni in boiling salted water, drain and season with a drizzle of oil.
Compose the dishes: arrange a layer of saffron sauce on the bottom, arrange a layer of ravioloni and finish with a nest/chuck of marinated zucchini.
Top with a few fresh mint leaves, a drizzle of oil and serve immediately.