Whisk together the milk, ricotta and egg yolk. Set aside.
Crisp up the garlic in a little oil, transfer to a small plate and set aside.
In a skillet/small frying pan slowly heat up the sauce mixture stirring with a whisk until hot but do NOT let it boil as the sauce might curdle. Remove from the heat, stir in the parmesan and season to taste.
Pour boiling water over the zoodles (enough to just cover them) and soak for about 30 seconds (just to heat them up). Drain well (you may want to place the zoodles briefly on some paper towels to remove any excess moisture).
Add the zoodles to the sauce, stir, adjust the seasoning as necessary, scatter the garlic and serve!