Combine1 teaspoon lime juice (reserving remainder for avocado-mango salad) and remaining rub ingredients in a small bowl until well incorporated.
Ribeyes
Allow thawed ribeyes to come to room temperature over about 20 minutes.
Preheat grill to medium heat.
Press prepared steak rub evenly across all ribeyes.
Place ribeyes on covered grill for 9-14 minutes, flipping occasionally, to achieve medium-rare (130-140 degrees Fahrenheit) to medium (140-150 degreesFahrenheit) doneness, as per a meat thermometer. Once removed from grill, allow to rest before serving with avocado-mango salad.
Avocado-Mango Salad
Combine mango, avocado, and onion in medium bowl.
Sprinkle with cheese and drizzle with reserved lime juice, tossing gently to coat, and season to taste with salt and black pepper.