In a food chopper chop garlic, onion, cilantro, and jalapeno. If you don't have a food chopper, chop ingredients finely by hand.
Place raw chicken, chopped ingredients, olive oil, lime juice, salt, and pepper in a large glass bowl. Stir until well combined. Cover and place in fridge marinating for at least a hour.
Preheat grill to medium to high heat. While preheating remove meat from fridge to warm up a bit.
Grill tenders for about 4-5 minutes on each side or until cooked through. Grill time can vary based off of temperature of the grill and size of tenderloins.
Remove from grill, let rest for 4-5 minutes.
Serve with favorite sides, on salad, or in my low-carb tortilla shells.