Roast the poblano peppers over an open flame or under the broiler until charred and blistered, then place in a plastic bag to steam; peel off the skins and slice into strips.
In a skillet, heat olive oil over medium heat, add chopped onion and sauté until translucent and fragrant, about 5 minutes.
Add minced garlic and smoked paprika to the onions, cook for 30 seconds until fragrant, then stir in the shredded chicken, season with salt and pepper, and cook until heated through.
In a blender, combine sour cream, milk, toasted cumin seeds, and a pinch of salt; blend until smooth to make the sauce.
Pour the sauce into the skillet with the chicken mixture, stirring to coat everything evenly, and cook until the sauce slightly thickens, about 3-4 minutes.
Preheat your oven to 375°F (190°C). Lightly butter the baking dish, then spread about 1/4 cup of the chicken sauce mixture at the bottom.
Warm the tortillas slightly to make them pliable, then spoon a generous amount of the chicken mixture onto each tortilla and roll tightly.
Arrange the filled tortillas seam-side down in the prepared baking dish, then ladle the remaining sauce over the top and sprinkle with shredded cheese.
Place the dish in the oven and bake for 20-25 minutes, until the cheese is melted, bubbly, and golden brown around the edges.
Remove from oven and let sit for 5 minutes; garnish with sliced poblano strips if desired, then serve hot and enjoy the rich, smoky flavors.
