Juice the lime into your food processor(or blender) and add the tequila, garlic, jalapeño, cilantro and salt and pepper into a food processor. Pulse until blended.
Add the Hellmann's mayonnaise and pulse 2 - 3 times - just to combine.
Add the chicken to a large plastic bag with the marinade. Seal and press the bags to ensure the chicken is completely coated.
Marinate in the fridge for 4 - 6 hours, or overnight.
Remove the chicken from the bag and grill over medium high heat for 6 - 8 minutes per side, or until cooked through.
Sprinkle with chopped cilantro and serve with lime wedges and sliced jalapeño.