In a large skillet over medium heat, add a splash of oil and sauté the chopped onion until translucent. Add the cubed chicken and cook until browned and cooked through, about 7-10 minutes. Season with salt, dried oregano, and ground cumin.
Once the chicken is cooked, add the sliced poblano pepper and cook for an additional 3-4 minutes until softened. Stir in the finely chopped chipotle peppers and enchilada sauce, allowing the mixture to simmer for a few minutes.
In a separate bowl, mix the shredded cheese, cooked rice, and fresh chopped cilantro. Lay a warm tortilla flat and spoon a generous amount of the chicken mixture on one half. Top with the cheese mixture and fold the tortilla over.
In the same skillet, add a bit more oil if needed and place the folded quesadilla in the skillet. Cook for about 3-4 minutes on each side until golden brown and crispy. Repeat with the remaining tortillas and filling.
In a mixing bowl, combine plain Greek yogurt (or sour cream), mayo, garlic, lime zest, and lime juice. Mix until smooth and creamy.
Slice the quesadillas into wedges and serve hot with the creamy sauce and diced mango on the side. Garnish with extra cilantro if desired.