Place cilantro, parsley, garlic, chile, shallot, white wine vinegar, lime juice, oregano, salt and pepper in the bowl of a food processor or blender.
Pulse a couple of times, adding olive oil while pulsing.
Reserve about 1/2 cup of marinade to use for sauce.
Pour remaining marinade over meat, turning to coat both sides.
Cover and refrigerate for 3 hours to over-night.
Remove meat from marinade, wipe most of it off with a paper towel and grill or BBQ to desired temperature.
Cut meat against the grain into thin slices with reserved Cilantro-Garlic Sauce.