2. Place the pepper on the grill and roast it on all sides until it is evenly blackened and blistered. Place the pepper in a bowl and cover with plastic wrap.
3. Turn the grill down to medium-high. Brush the chicken breasts with oil and season them with salt and pepper. Grill the chicken breasts on both sides until they are cooked through, about 6 minutes per side. Transfer the chicken to a cutting board and cool.
4. Meanwhile, separate the tortillas into 2 stacks, wrap them in foil and warm them on the grill.
5. Remove the pepper from the bowl and peel it. Remove the stem and seeds. Cut the pepper into strips and place them in a medium bowl.
6. Cut the chicken into strips and add them to the bowl with the peppers. Sprinkle the chicken and peppers with the fresh lime juice.
7. Fill the tortillas with chicken and peppers, sour cream, lettuce, tomatoes, cilantro leaves and jalapeño pepper. Serve 2 tacos per person with lime wedges on the side.