For lunch today, we had intended on eating the Roast Beef Sandwich at Darwin Cafe — SoMa's not-so-best-kept secret, a small cafe/sandwich shop tucked away on Ritch and Bryant — but we were either handed the wrong box or, most likely, swiped another person's order by accident. We can get aggressive at Darwin. The place is that good. And since it's packed at lunchtime with long lines, we tend to get grabby. But what a mistake it was for if we took our original order, we would never have had the pleasure of experiencing their Grilled Cheese with Fromage Blac, the airiest and fluffiest yet most complex grilled cheese we've crammed down our throat in ages.

We imagine Darwin's remarkable chef and staff wouldn't care much their fare labeled "fluffy" — manly men seem to run the cozy bistro — but that's just what it is: puffy, fluffy. And we mean that in the best way possible. Two robust toasted pieces of bread hold together not only an airy, climactic wad of fromage blanc, but also white cheddar, date jam, hazelnuts, and balsamic. You can add a slice of proscuitto for a mere $1, which we strongly recommend. Sweet, savory... but more on the savory side. You get the idea.

While this grilled cheese isn't as intentionally filling as, say, a sandwich one might find at South Park's American Grilled Cheese, it's also not a treat you should eat each day. Because you'll get large. Too large.

Besides this dairy orgy we happened to come across, Darwin also serves other equally phenomenal sandwiches (Bay Shrimp Melt, the aforementioned Roast Beef) as well as a slew of well-dressed salads that boast plenty of meat. They also serve (delightful) coffee. However, for lunchtime, be sure to get there early as the line grows longer and longer from noon to 2pm. Otherwifdse, it's a great spot for supper. Less packed, calmer, the perfect SoMa spot to sit at the bar for wine and good grub.

Oh, and to the patron who ended up with our roast beef? We hope you enjoyed it. We'll try to be more careful in the future.

Darwin Cafe: 212 Ritch (between Brannan & Bryant), SF, 415-800-8668