By midtown, I am guessing you mean somewhere from St. Clair-ish to Eglinton-ish, ranging a bit east and west of Yonge? If I am wrong, please correct me.
Little Sister has already been mentioned, for tasty Dutch-Indonesian food and fun cocktails. Make sure you get the vegetable dishes, which are some of the highlights.
Tabule’s original location on Yonge, north of Davisville remains great for Lebanese. The garlic tomatoes are a must.
I can’t think of many truly hole-in-the-wall places in the midtown area. Downtown in the east and west stretches there are more. Swatow as mentioned above. Chinese Traditional Buns is another in that Chinatown. See the Kensington Market thread for many others, particularly for Latin American (e.g., Jumbo Empanadas). Heading east, there’s Pizza Pide for Turkish pide, White Lily Diner, GB Hand Pulled Noodles, Hastings Snack Bar for Polish, Lady Marmalade for brunch, Completo for great Chilean steak sandwiches, and so on.
