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Good cheese grits. To make some at home, I recommend McEwan and Sons, which is a gristmill based in Wilsonville, Alabama. (You can order them online.) Amazing organic stone-ground grits.

Po'boys, shrimp etouffée, gumbo, and muffalettas in New Orleans.

Fresh gulf shrimp at almost any dive along the Gulf Coast.

She-crab soup in South Carolina.

Biscuits and gravy.

White BBQ sauce.

I visited Egypt before the protests began and sampled a variety of food. Koshari (or koshary) is definitely common, as well as hummus, pickled baby eggplant, baba ghanoush, hibiscus tea, mango juice, and a delicious, thin pita-like bread that the locals said they didn't have a specific name for (They just called it bread. I think they thought I was crazy for asking!)—it was very thin and soft but had a pocket in the center like pita. I'm still on the hunt for a recipe to replicate it. On the Mediterranean coast, it's all about seafood, mainly shrimp and calamari.

I would second the recommendation for Tartine Bakery in SF.

Some other recommendations:
1. U-Lee on Hyde Street.
I highly recommend this restaurant! It’s a tiny hole-in-the-wall. It’s run/owned by Chinese immigrants so the food is authentic and delicious. No real drinks here except beer and boxed wine. The food is GREAT and very cheap. Try the pot stickers.
1468 Hyde St at Jackson (right on the cable car line)

2. Suppenkuche—Great, fun place. It’s a German restaurant that is very low-key and casual. The wait staff and bartenders are all German (at least when I went). They have German beer on tap served in large steins, if you’d like. The food is great. Very authentic. Great sauerkraut. Make reservations.
601 Hayes Street near the Civic Center

Hope you have a great trip!

The 100-mile diet. It's great in theory but completely impractical for many regions of the country. Our diets wouldn't be as varied and some of us would be missing out on some very important things like wine!

Yes! Great job. They are gorgeous!!

I agree with the recommendations for Pomelo and Tartine. Both are excellent.

I know German food wasn't on your list, but I love Suppenkuche on Hayes (I think 601 Hayes). Authentic German food, great sauerkraut.

Another nice place is Absinthe near the Opera House. The menu changes weekly and they always have great food. I've never been disappointed.