Place each boneless skinless chicken breast between parchment paper or in an unsealed gallon-size Ziploc bag. Use the smooth side of a meat mallet to pound each chicken breast to ½ inch thickness.
Add 1½ tablespoons extra virgin olive oil to a 10 to 12-inch cast iron skillet over medium-high heat.
Season both sides of the boneless skinless chicken breasts with kosher salt and cracked black pepper. Add the chicken to the pan of heated olive oil and cook for 6-7 minutes per side until golden brown. Transfer the chicken to a plate and set it aside.
Add the remaining extra virgin olive oil to the pan over medium-high heat. Saute the finely chopped onion for about 3 minutes until the onion begins to soften and turn opaque. Add the minced garlic and grated ginger. Cook for about another 2 minutes. Lower the heat to medium.
Add the unsweetened coconut milk, chicken broth, lime zest, lime juice, ¼ cup cilantro, ground cumin, ground coriander, and red pepper flakes. Stir to combine. Continue cooking for another 5-7 minutes until the sauce begins to thicken.
Return the chicken to the pan and continue to cook for another 5 minutes. Remove from the heat and garnish with the lime slices and remaining cilantro. Serve while hot over rice.
If the coconut milk appears separated in the can, simply give it a good stir to combine the cream and liquid before using it in the recipe.
If you desire a thicker sauce, simmer it a bit longer to let it reduce further. On the other hand, if you prefer a slightly lighter sauce, you can use less coconut milk and more chicken broth.
Make sure the chicken reaches an internal temperature of 165°F on a meat thermometer.