I had to substitute a few of the items that I couldn’t find at the grocery store. Instead of the porcini mushrooms, I used one fresh Portobello mushroom, chopped into small pieces, and eliminated the first soaking step. I also couldn’t find fresh chives, so I had to use dried chives. My last substation was to use a blend of Parmesan, Romano, and Asagio cheeses rather than the Parmigiano-Reggiano. All three of these substitutions worked out just fine.
I have to admit, when I first started cooking this dish, the thin sauce made me wonder if I’d made a mistake. But once it was done, I was very happy that I’d resisted the urge to add more cheese to the sauce. The finished dish is very light, smells wonderful, and really accentuates the flavor of the mushrooms rather than covering them up with a heavy cheese sauce. It was very easy to make, and hard not to eat the whole pan! Plus it reheated well, which is always a plus when cooking for one or two.