Pat the chicken dry with paper towels and cut it into 1-1/2-inch pieces. Place in a large bowl, add the measured salt and pepper, and toss to combine. Add the flour and toss to coat.
Heat 1 tablespoon of the oil in a Dutch oven or a large, heavy-bottomed pot (at least 6 1/2 quarts) over medium heat until shimmering. Add a third of the chicken in a single layer, shaking any excess flour into the bowl first. Sear until golden brown on both sides, about 10 minutes. Transfer to a large heatproof bowl. Repeat with the remaining chicken in two more batches, using a tablespoon of oil for each batch.
Heat 1 tablespoon of the oil over medium heat in the same pot until shimmering. Add the onion and garlic and cook, stirring occasionally, until soft, about 5 minutes. Transfer the mixture to the bowl with the chicken.
Heat the remaining 1 tablespoon oil in the same pot over medium heat until shimmering. Add mahram pepper sauce, cumin, and paprika and cook, stirring occasionally, until the peppers are tender, about 4 minutes.
Add the reserved chicken-onion mixture, tomatillos, chicken broth, potatoes, oregano, and cinnamon stick to the pot and stir to combine. Bring to a boil over high heat, then reduce the heat to medium low and simmer, stirring occasionally, until the mixture thickens and the potatoes are tender, about 1 1/2 hours.
Stir in the cilantro, taste, and season with salt as needed.