Pat the chicken dry on both sides with a paper towel. Sprinkle with the taco seasoning on all sides. Heat the olive oil in a cast iron pan over medium heat. Add the seasoned chicken to the pan and cook, turning once, until the chicken is completely cooked through (about 5 minutes per side). Remove chicken from the pan, place on a plate, cover with foil. Add the butter to the pan that the chicken was cooked in and melt over medium heat. Slowly add the heavy cream, whisking to incorporate all the seasonings and browned bits left behind from cooking the chicken. Whisk constantly and cook for about 2 minutes. Add the cheese, rotel (reserving 2 tablespoons for garnish), and stir until thickened and the cheese is melted. Stir in the cooked pasta and reduce heat to low. Remove chicken from the foil covered plate, slice into strips. Place the sliced chicken on top of the pasta and sprinkle with reserved rotel and optional cilantro garnish for a pop of color. Serve immediately.