After midnight deep in the heart of Beşiktas, these two gentlemen can be found slinging grilled sandwiches of thin, sliced sucuk, peppers and tomatoes. It's one of our favorite street snacks, and one of the perfect follow ups to a cold one or four.

In the Laz language, “si sore” means, “where are you?” At least twice a week for past few years, our answer to that question at lunchtime would be, “We are at Pera Sisore.” This little restaurant in the Asmalımescit area became one of our go-to lunch spots by serving some of the best Black Sea food around town. But after a disagreement, the two partners of the restaurant went their separate ways and the quality at Pera Sisore, sadly, took a turn for the worse. We were feeling a bit lost for a period, not knowing where to go for a quick, honest lunch of hearty Laz fare. The Black Sea area is Turkey’s culinary misfit – it's not really about kebabs or mezes. If anything, the food there seems to have been mysteriously transplanted from the American Deep South.

In the Istanbul neighborhood of Kurtuluş, home to a large Armenian population, a number of shops are decorated on account of Easter, and the smell of traditional sakızlı Paskalya çöreği--puffy loaves of ever-so-slightly sweet bread baked with mastic gum--is thick in the air.

Fresh pomegranates await to be squeezed into juice near Istanbul's iconic Grand Bazaar .

Tucked away in an alley in Istanbul’s Aksaray neighborhood, Şirket Alahdab is a small grocery store overflowing with Syrian staples: pickled baby eggplants, dried leafy greens, cans of clotted cream for desserts. When we enter the store, Istanbul temporarily fades away and Damascus or Aleppo take its place. “All real,” the clerk declares proudly, as he shows off his goods. “Smuggled from Syria.”

As part of CB's "Usta All-Stars" card project, our intrepid researcher Ali Akas went around town interviewing street food vendors about their work, the food they serve and some of their trade secrets. Besides the cards, another result of Ali's work was this map, which plots the relative locations of some of Istanbul's finest vendors.

A proper way to start one's day is with a fresh cup of black tea from the wonderful tea master Bayram in Karaköy's 16th-century Kurşunlu Han building. It's the first stop on our Two Markets, Two Continents walk.

Wave after wave of migration from Anatolia has bestowed upon Istanbul a population of 15 million at bare minimum, with countless pockets of the city representing villages and districts from every last corner of the country. In the neighborhood of Feriköy, those originally hailing from the eastern province of Erzincan have managed to consolidate their presence on an entire street. Lined with a number of restaurants and shops selling fresh goods typical of the province, and a row of village associations established for the purpose of maintaining cultural ties between those living in Istanbul and their relatives back home, Feriköy's Gediz Sokak is all about Erzincan, a land of sheep and mountains famed for its dairy products.

“No hamsi, no money.” Mert Kanal hoses down empty Styrofoam containers and surveys the leftover catch in his market in Sinop, on Turkey’s Black Sea coast. The gulls squawk, fighting over scraps on the dock while fishermen tidy their nets for another night of fishing. The hamsi, or anchovies, are gone for the season, moving up the coast in dwindling numbers as hulking factory ships chase them. While mackerel, turbot and whiting are all fair game for fishmongers, hamsi holds a special place in Turkish cuisine. Unlike the slimy, salty canned form of the fish reserved for eccentric pizza toppings in North America, anchovies are eaten fresh in Turkey. Lightly battered, quickly fried and served with a slice of lemon, hamsi are gobbled down by the kilo, bones and all.

A fresh walnut is completely different from the type found in a package on a supermarket shelf. The nut is pale and soft, the flavor light and creamy, with not a trace of bitterness. It almost melts in your mouth. Rarely is it possible to eat just one. I can vouch for this because, last autumn, I ate more walnuts per day than I would usually consume in a year, thanks to a six-week stint on an Anatolian walnut farm. Having decided to move from London to Istanbul for work, my husband and I wanted to begin by improving our Turkish. We stumbled upon Tatuta, a matchmaking site for organic farms in Turkey and volunteers willing to lend a hand. It was something of a challenge for us – a pair of city dwellers with little agricultural experience – to come up with a compelling account of why we would be useful. In the end, we just decided to sound enthusiastic and willing to learn.

Metin Akdemir is a filmmaker based in Istanbul. In 2011 he made a short film about street vendors in the city. The film, “Ben Geldim Gidiyorum” (“I’ve Come and I’m Gone”), won several awards in Turkish and international film festivals, and we think it’s a very valuable piece of work that captures a side of Istanbul’s culture that is slowly disappearing.

When we picked up a cab from Meşhur Unkapanı İMÇ Pilavcısı recently, it turned out the driver had just been there for a refuel himself. Sensing a captive yet interested audience, he held forth all the way to Beyoğlu about where to eat well and cheaply – without stomachaches ensuing – in Istanbul. We’re always happy to discuss the finer points of kuru fasulye (stewed beans), but this driver seemed to have a particularly deep interest in the subject. After debating the merits of various canned brands (“Yurt” brand or nothing, in case you were interested), he dived into the subject of soup.

My wife, Kurdish in-laws and I are enjoying an early meal at Gabo, one of Diyarbakır’s most successful new restaurants. It gets dark early this time of year in the city, and the dry air carries the ayaz chill, which engenders a need for a hearty soup and hot tea. The owner, Cahit Şahin, shares stories of the place’s beginnings. “When we applied for a restaurant license, City Hall just laughed,” he tells us. “‘For a vegetarian place?’ they said, ‘In Diyarbakır? Go ahead! It doesn’t matter if we grant you one or not. You’ll go under in three months!’” But that was nine months ago. Gabo, which bills itself as the predominantly Kurdish southeast region’s only vegetarian restaurant, is thriving. In fact, they are doing so well that Şahin and his fellow owners are planning to open franchises in the western Turkish city of Tekirdağ and in Istanbul. As Şahin talks, he gestures at the bustling café around him. “We used to work as tutors for students preparing for their standardized exams. We were just sick of the rat race, of always being tired and worn out. I envisioned a cozy alternative joint where I could drink tea, listen to jazz and play backgammon with my friends.” He laughs. “We haven’t touched a backgammon board since we opened the doors!”

Editor’s note: To give 2015 a proper send-off, we’re taking a look back at all our favorite eating experiences this year. Hamo’nun Yeri The nohut dürüm, a simple wrap of mashed chickpeas, peppers, parsley and spices, may be a popular breakfast choice in certain districts of the southeastern province of Gaziantep, but we'll eat it anytime and are prepared to travel far and wide to do so, as this treat is by no means common in Istanbul. Hamo'nun Yeri is located in Güngören, a densely packed working-class district located well outside the radar of tourists and more affluent Istanbulites. Made with bread hot out of the oven from the family's bakery down the block, the dürüm – and a chat with the friendly Gül brothers – is more than worth the trip. Address: Güngören Merkez Mah., İkbal Sokak 9/B, Köyiçi Telephone: +90 535 016 0316 Hours: 7am-10pm —Paul Osterlund

Editor's note: The chef and owners of Mekan have moved on to a new location, which they've named Mari. We're sorry to report that Mekan itself has since gone downhill. In the great multicultural Anatolian kitchen, questions about the ethnic or national origins of foods are often cause for forks and knives to fly. A porridge called keşkek is a hot-button diplomatic issue between Turkey and Armenia, and we won’t even get started on the ongoing baklava debate. So what to make of this cuisine that draws influences from every corner of the former Ottoman lands, a territory stretching from the Balkans to North Africa? The answer might be in a simple term that’s becoming popular among Turkey’s minorities. The word Türkiyeli means “of Turkey” and differs significantly (and quite intentionally) from the word Türk, which often adds ethno-religious shades to nationality.