Place the steaks and the marinade in a glass baking dish, cover with plastic wrap and place in the fridge for 12 to 24 hours. Turn the steaks every 4 hours.
To make chipotle sour cream, mince/puree the chipotle peppers into the sour cream. Let stand for a few minutes and taste. For a spicier chipotle sour cream add additional chipotle peppers. You can make this the day before. Store in the fridge.
About 45 minutes before you grill the steaks, remove from the fridge and let stand at room temperature.
Preheat the grill to medium-high heat.
Cook the steaks on the grill until they reach an internal temperature of 135°F for medium rare doneness. Remove the steaks from the grill and let stand for 5 minutes before slicing.
Slice the steaks thin across the grain and place on serving platter.