Boil a pot of water. Add enough salt (not listed) so that it's about 1% of the water, and boil the spaghetti. Stop the heat and drain 1 minute before the instructed time.
While boiling the spaghetti, mix together the sauce ingredients in a heatproof bowl that you can use for a double boiler.
Once the spaghetti is cooked, use a pair of tongs to add it to the bowl with the sauce mixture from Step 2. Don't throw away the pasta water yet, as you'll be using it for the double boiler in the following step!
Combine the pasta and sauce, letting the bowl warm in the residual heat of the pasta water. Once the sauce starts to thicken, you're all done.
Serve on a plate, top with shredded nori and enjoy.
Story Behind this Recipe
The craving for carbonara strikes! But I only have milk in the fridge. And throwing away the egg whites would be such a waste. Then what about making use of a whole egg and the milk, and adding Japanese dashi for extra depth...?
Powdered dashi stock has sodium in it, so you don't have to worry about adding too much salt. It's good without toppings or additions like bacon and vegetables, but try different combinations of your own (mushrooms would probably work well).