Place the chicken breast in a ziplock bag and add a little avocado oil, making sure to coat both sides.
Seal the bag and use a heavy object like a bottle to flatten the chicken to an even thickness.
Remove the chicken from the bag and place it on a plate.
Season the chicken with kosher salt and black pepper.
Let the chicken sit at room temperature for 15 minutes while you prepare the jalapeño cream sauce.
To make the sauce, drain the canned jalapeños and add them to a blender or food processor.
Add the Greek yogurt, garlic, lime juice, and cilantro, and blend until smooth.
Preheat the grill to high heat.
Place the chicken on the grill and cook for about 3 minutes per side, or until cooked through.
Brush the chicken with the jalapeño cream sauce during the last 30 seconds of cooking.
Serve the grilled chicken with the remaining jalapeño cream sauce on the side.
