Combine all marinade ingredients in a bowl and mix to combine.
Place hens in a freezer bag and add marinade (reserve ⅛ cup marinade for serving). Refrigerate overnight up to 24 hours.
Heat grill to 450 degrees. Grill the hens for 7-10 minutes per side, or until internal temperature reaches 160 degrees.
Let rest for 10 minutes and serve with reserved marinade and fresh limes.
Notes
This marinade would also be delicious on beef, pork, shrimp, fish, or shoe rubber.
The internal temperature of the hens should be 160F when removed from the grill. I like to use an instant read thermometer like this Thermapen to get a good temperature reading.
If the skin starts to get too dark turn down the heat or move to a cooler part of the grill.