In a large mixing bowl, combine orange juice, olive oil, cilantro, lime juice, lemon juice, white wine vinegar, cumin, salt, and pepper, jalapeno, and garlic; whisk until well combined. Reserve ⅓ cup of the marinade; cover the rest and refrigerate.
Combine remaining marinade and steak in a large resealable freezer bag; seal and refrigerate for at least 2 hours, or overnight.
Preheat the grill to HIGH heat.
Remove steak from marinade and lightly pat dry with paper towels.
Add the steak to the preheated grill and cook for another 6 to 8 minutes per side or until desired doneness. Note that flank steak tastes best when cooked to rare or medium rare because it's a lean cut of steak.
Remove from heat and let the steak rest for 10 minutes. Then, thinly slice it against the grain, garnish with reserved cilantro mixture, and serve.
Stovetop Method
Heat a large cast iron skillet (preferably cast iron grill pan) over high heat until hot. Add steak to the skillet and cook for 6 to 7 minutes per side, or until desired level of doneness.
Notes
Marinate for Flavor: Always marinate the flank steak - this not only imparts flavor but helps tenderize the meat.
High Heat for a Short Time: Flank steak is best cooked quickly over high heat to achieve a nice char on the outside while keeping the inside tender.
Mind the Grain: Always cut flank steak across the grain. This shortens the muscle fibers and makes the steak easier to chew.
Rest Before Slicing: Once you've grilled the steak, let it rest for about 5-10 minutes before slicing.
Add Finishing Touches: After grilling, consider squeezing fresh lime juice or sprinkling fresh cilantro over the steak for added flavor.
Use Leftovers: Carne Asada is versatile. Use leftovers in tacos, burritos, salads, or quesadillas for a quick and flavorful meal.
Steak Guide to Doneness:
125°F to 130°F internal temperature for RARE
135°F to 140°F internal temperature for MEDIUM RARE
145°F to 150°F internal temperature for MEDIUM to MEDIUM WELL
150°F internal temperature for WELL DONE
The FDA recommends that steak be cooked to an internal temperature of 145°F.