By Alex Lauer I’ve been using Stasher bags for a couple years now, but I’m not normally one to evangelize about mundane products. Oh, I’ll tell everyone who comes to my house about how great my espresso machine is. Reusable silicone bags aren’t as seductive as silky espresso, though. So it continues to surprise me that when I do have guests over for dinner and I pull one of my multi-color Stasher bags out of the refrigerator — one holding some parmesan I’ll grate over a salad, or a sliced lemon to squeeze over pasta — they’ll often be delighted by the baggies. They’ll ask, with serious interes…