Very thinly slice half of the lime and set aside. Reserve (or juice) the other lime half for sprinkling.
Lightly pound chicken evenly to about ¾ inch thick and dry with a paper towel. Butterfly chicken by cutting half way through the long side of the breast, crossways, to create a flap. Do not cut all the way through.
Sprinkle 1 teaspoon cumin, ½ teaspoon salt, and ¼ teaspoon pepper on the inside of the chicken breasts. Divide lime slices evenly, place on the breasts, and close the flap. Sprinkle the outside of the chicken with remaining 1 teaspoon cumin, 1 teaspoon salt, and ¼ teaspoon pepper.
In a large skillet on medium heat, melt olive oil and 1 Tablespoon butter. Once melted and bubbling slightly, add chicken top side down and fry for 4 minutes, or until browned.
Flip chicken and add remaining butter. Squeeze some lime juice over the breasts and swirl the pan to spread the butter. Cook for 5-7 minutes, until chicken is cooked through and reaches an internal temperature of 165°F.
Pour pan juices over chicken and sprinkle with fresh cilantro if desired. Serve with cilantro rice. Remove lime before eating if preferred.
Notes
Marinate the chicken for 1-2 hours or overnight for maximum taste.
Opt for freshly squeezed lime juice instead of bottled juice to add a vibrant tanginess to the chicken.
Taste the marinade before adding the chicken and adjust the cumin and lime levels to suit your preference. Add more if desired.
Leftover chicken will keep in an airtight container in the refrigerator for up to 4 days, and 1 month in the freezer.