I first learned to really love butter in a suburban diner called Corfu. Located about 45 miles outside of Chicago, the restaurant looked like someone had gutted an old Denny’s, saved the furniture and then painted a large-scale mural of coastal Greece before finally putting the chairs and tables back on the dining room floor. My mom and I went there for lunch so often that we eventually established a kind of routine. We’d go around 1 p.m., after the bulk of the lunch rush, slide into the merlot-colored pleather booths and peel the vinyl menus off the freshly wiped tables. Our orders remained unchanged for years. She’d get the chef’s…