Potbelly Rooftop Cafe (https://goo.gl/maps/khWShXheJjv) - Food from the eastern part of India. Order 'Bhojpuri Thali' and 'Madhubani Thali', should be enough food for 2 people.
Nagaland Kitchen (https://goo.gl/maps/XZE7yRuimGK2) - Food from the North eastern part of India. Order the dry fried pork here, along with 1 starter, which should be enough for 2 people.
Rajinder Dhaba (https://goo.gl/maps/cR2roGsUiit) - This is a very popular place to eat on the street, so you should head out to only in the evening. There will probably be no tourist here, but this is an authentic and raw experience. If you are traveling with someone who does not like crowds, I would avoid this place as it gets a bit rowdy. If you make it, then order the following items (they are all from the coal grill): Paneer Tikka (Cottage cheese grilled), Chicken Malai Tikka (Chicken in cream grilled), Shammi Kebab (Mince lamb cutlets), Mutton Seekh Kabab (Minced lamb grilled), Fish Tikka (Grilled fish). I think 4 of these + 3 Roomali Roti (very thin round bread) should be good.
Dilli Haat (https://goo.gl/maps/Lm2BHZnEsEy) - This is a place made for tourist. You can find art, crafts and souvenirs from all over India, along with Food from all over India. It is touristy, but even Delhi-ites go there often. The art and craft stuff is definitely genuine, but 2-3 times expensive compared to a regular street market. If you end up here, I would recommend you eat the following: 'Pork momos (dumplings) from the Nagaland Food Stall' and 'Sabudana Khichdi (Tapioca cooked like rice) and Modak (sweet dumplings) from the Maharashtra Food Stall'. Nagaland is a state in the north east of India, and Maharashtra is s state in the west of India.
Karnataka Bhavan (https://goo.gl/maps/NgJcQJqYGjP2) - This is a place from the south of India. Order 'Idly Vada with Sambar', 'Masala Dosa' and 'rava kesari'.
Sarvana Bhawan (https://goo.gl/maps/GJh4bD2MBBF2) - Similar to the above, but in the center of Delhi. Order the same stuff as in #5.
Keventers Milk Shake (https://goo.gl/maps/d49eQziQ1gM2) - This is an old and very different milk shake shop. A bit hard to find, but look out for the crowd of people around it. Order any milkshake flavor.
Nizam's Kathi Kebab (https://goo.gl/maps/N4F2XYJd4DS2) - Order any roll from the menu. Be advised, it is very oily.
Haldirams's (https://goo.gl/maps/Z2tj3L94s4L2) - This is the best place to try street food from Delhi, but in sort of hygienic conditions. Order: Aloo Tikki (potato pancakes), Chole Bhature (chick peas with fried bread), Chat Papdi (Crisps with jogurt, mint and some other things), Gol Gappe (Hollow crisy dough filled with water and sauce), Samosa (a snack) and Kachori (another snack). Order tea with any of these.
Gulati's (https://goo.gl/maps/TcT5LZG67sP2) - This is one of the best places to eat Butter Chicken, so either go early (1830/1900) or book a table. Order: Half Butter Chicken with 1 Naan and 1 Pudhina Parantha, and 1 Mutton Biryani (Lamb with Rice). This is will be a good amount of food for 2. Immediately outside the restaurant is a place with some sweets, order Falooda Kulfi, an Indian ice cream.
Khan Chacha (https://goo.gl/maps/CGJGRZgH9Zx) - This is one of the best places to eat wraps. Order: Mutton Kakori Roll (The softest lamb kebab in the world), Chicken Malai Tikka Roll (Creamy Chicken roll) or Fish Tikka Roll. You can add a Chicken Biryani (Chicken and Rice).
Carpe Diem (https://goo.gl/maps/BkXHfgGGQkE2) - Started as a restaurant for wanna be hippies, not sure how it is. The view is nice, and they serve a decent pizza.
Noodles in hot sauce - In McLeod ganj, you will find usually middle aged/old asian looking men selling noodles only, with a watery sauce. It is hot as hell, but great to have in winters when it is freezing.
Tibetian food - Since this is a place where Tibetians took refuge, and then stayed over, you will find authentic tibetian food here. Unfortunately the places I knew are not on google maps but I am sure you will find something while walking on the street. The only one I can find was Norling (https://goo.gl/maps/H4yFqVd6rfQ2). Order a 'Thukpa' and Dumplings here.
Lung Ta Japanese restaurant (https://goo.gl/maps/9Ah6hYinYHp) - Since Japanese buddhists visit this town, there are a few Japanese restaurants. This one is vegetarian.
Nick's Italian Kitchen (https://goo.gl/maps/rq6NzfkDNT32) - Italian food.
Chocolate Log (https://goo.gl/maps/RYXYrmSdRE42) - Cafe in a quiet part of the town.
Khaana Nirvana (https://goo.gl/maps/7QLhhczARcB2) - Community cafe (vegan). Their apple cider is pretty good.
Woeser Bakery (https://goo.gl/maps/Rg93Lbp3Xwy) - Cafe.
German Bakery (https://goo.gl/maps/3Ba9vWxxxRB2) - Cafe.