What you will need:

4 boneless, skinless chicken breasts

For the marinade:

3 limes, juiced
2 tablespoons olive oil
3 cloves garlic, minced
3 tablespoons tequila
3 tablespoons orange-flavoured liqueur
2 tablespoons liquid honey
1 tablespoon minced cilantro

Steps to yummy goodness:
For the marinade:
In a large, resealable plastic bag, combine the lime juice, olive oil, garlic, tequila, orange liqueur, honey and cilantro.

Add the chicken.

Seal the bag and work the marinade through the chicken with your fingers. Refrigerate the chicken for at least 2 hours or for up to 6 hours.

Steps for grilling:
Preheat greased barbecue grill to medium-high heat. Remove the chicken from the marinade and discard the marinade.
Grill the chicken, turning once, until no longer pink inside, 6 to 8 minutes per side.
Let stand for 6 to 8 minutes. Serve immediately whole or sliced crosswise.

* Side Note *
The most common orange liqueurs are Triple Sec, Cointreau and Grand Marnier. Use the one you like best.