Combine all the spices for the Spanish seasoning mix in a small bowl, then split into two portions and set aside.
Slice one half of the lemon thinly for garnish and juice the other half.
Place the chicken in a bowl, drizzle with 2 tablespoons of oil, and toss well to coat.
Rub half of the seasoning mix evenly over both sides of the chicken pieces.
Heat the remaining 1 tablespoon of oil in a large skillet over medium heat.
Sear the chicken for about 2-3 minutes on each side until it develops a golden brown crust; then remove it from the pan and set aside.
To the skillet, add the rice, chicken broth, lemon juice, and the remaining seasoning; stir everything together.
Nestle the chicken pieces back into the pan on top of the rice.
Cover the pan and let cook for 20-25 minutes until the rice is tender, the liquid absorbed, and the chicken is thoroughly cooked.
Sprinkle with chopped cilantro or parsley and garnish with lemon slices before serving immediately.