Whisk together the serrano peppers, garlic, cilantro, olive oil, chili oil, orange juice, lime juice, vinegar, ancho powder, cumin and salt and pepper in a medium sized bowl until well combined.
Alternatively, you can process the ingredients in a food processor or blender until smooth.
To use the marinade, add it to a large sealable bag with the steak and rub it thoroughly into the meat. Seal and refrigerate for at least 2 hours, or overnight for more flavor penetration.
Discard the marinade, then grill the marinated steak on the grill for 8-10 minutes per side, or until cooked to your liking. 135 degrees F is medium-rare. Let the steak rest for 10 minutes, then slice it against the grain into bite-sized pieces.
Serve the steak onto warmed tortillas and top with roasted jalapeno, avocado, tomato, cilantro, chili flakes and hot sauce.