DC is known for its Ethiopian food, seems like at least one of your meals should have that, no? Unless there's better to be found at home?
Acadiana is an excellent choice.
I had a pretty good meal at Jaleo last year but it seems like you have to order very carefully to get the best dishes on the extensive menu. I was disappointed by the patatas bravas but liked the pan con tomate and asparagus we ordered.
We also greatly enjoyed Zaytinya, his mezze place, nearby. Perhaps a bit more than Jaleo (thought the Spanish restaurants in NYC a bit better). Try the Kibbeh Nayeh (beef tartare), seasonal mushrooms with dates and toasted almonds, crispy eggplant, the Arayes (grilled ground lamb and tahini, stugged into a pita), and/or their famous Greek yogurt dessert with pistachio and apricots.
I would say that Rasika is a not-to-be-missed restaurant. Creative Indian, slightly on the upscale side. They're open for weekday lunch, if that helps your schedule. Fabulous Tawa Baingan (eggplant, spiced potato, olive oil, peanut sauce). Nicely cooked eggplant rounds, that were so very tender, alternated with this deliciously spiced potato puree. The Palak Chaat (crispy baby spinach, sweet yogurt tamarind, date chutney) more than lived up to the raves. Deep fried spinach, creamy yogurt, sweet chutney. Marvelous textural contrasts all around. We also loved the slow heat of the Chicken Green Masala, especially when we dipped pieces of our garlic naan in the sauce or ate the fragrant rice with the sauce alone. They are also known for a black cod dish, which we didn't try.
Also good and near Penn Quarter:
Proof (wine bar where they'll do 2 oz pours so you can try more, excellent small plates, particularly liked the "pho" terrine)
Luke's Lobster (counter service/takeout place for lobster rolls, and offshoot of the NYC one)
Paul Bakery (French chain, excellent brioche doughnuts and croissants, haphazard service though)
Also if you like cocktails, The Columbia Room is fantastic and focused on hand-crafted, seasonal cocktails.
The menu is $64 including tax and tip for 3 drinks, a small plate, and a snack to finish. The drinks include one welcome drink, one special of the night, and the last of your choosing (can be ordered by name or by giving your preferences, i.e., boozy, refreshing, citrus or no citrus, using gin/rum/etc). There are two bartenders for the 10 seats. On my last visit I had a fresh white peach bellini, a mezcal watermelon and basil smash, and a gin fizz made with sour cherry preserves.
Note that you MUST make a reservation, and they are only open Tuesday through Saturday. The bar is tiny, and they do a 4 turns a night. Once your two hours is up at the bar, you can move to the banquette and have an additional 4th or 5th drink if you like.