Preheat the broiler. Put the poblanos skin-side up on a foil-lined broiler pan; broil until charred, about 5 minutes. Transfer to a bowl, cover and let sit about 5 minutes. Peel and cut into 1/2-inch strips.
Rub both sides of the chicken with the chili powder and salt to taste. Heat 2 tablespoons olive oil in a skillet over medium-high heat. Working in batches, cook the chicken until browned, about 30 seconds per side. Transfer to a plate. Add the remaining 1 tablespoon olive oil to the skillet, then cook the onion until softened and browned, about 5 minutes. Reduce the heat to medium and add the poblanos and garlic. Cover and cook 5 minutes.
Meanwhile, cook the fries as the label directs.
Cut the chicken into 1/2-inch strips and add to the skillet along with the cream. Cook, uncovered, until the chicken is cooked through and the sauce thickens, about 5 minutes. Divide the fries among plates and spoon the chicken and sauce on top. Serve with lime wedges, if desired.
Per serving: Calories 761; Fat 48 g (Saturated 17 g); Cholesterol 127 mg; Sodium 474 mg; Carbohydrate 50 g; Fiber 5 g; Protein 32 g