Preheat your oven to 450°F (230°C). Place the poblano peppers on a baking sheet and roast them for about 15 minutes, turning occasionally, until the skins are charred. Remove from the oven and let them cool. Peel off the skin, remove the seeds, and chop the peppers.
While the peppers are roasting, season the chicken breasts with salt, pepper, smoked paprika, and cumin.
In a large skillet, heat olive oil over medium-high heat. Add the seasoned chicken breasts and cook for about 5-7 minutes on each side, or until they are cooked through and golden brown. Remove from the skillet and set aside.
In the same skillet, add the diced onion and cook until translucent, about 3-4 minutes. Add the minced garlic and cook for an additional 1 minute until fragrant.
Pour in the chicken broth and bring it to a simmer. Stir in the heavy cream and chopped roasted poblano peppers. Allow the sauce to simmer for about 5 minutes until it thickens slightly.
Add the seared chicken back into the skillet, coating it with the creamy sauce. Let it simmer for another 2-3 minutes to heat through.
Taste the sauce and adjust seasoning with more salt and pepper if necessary.
Remove from heat, and sprinkle with fresh cilantro if desired.