In a small bowl, whisk together orange juice, lime juice, white vinegar, olive oil, jalapeno, garlic, salt, and pepper.
Place the steak into a shallow dish. Pour the marinade over the meat. Refrigerate and let marinate for 30 to 60 minutes.
Meanwhile, make the pico de gallo by combining tomatoes, onion, cilantro, jalapeno, and lime juice in a bowl. Toss together and salt to taste.
Heat a large heavy skillet over high heat. Cook your steak for 4 to 5 minutes per side, or until it reaches medium-rare. Turn off the heat and let steak rest in skillet 5 minutes. Remove from skillet and slice against the grain.
Return the steak to the skillet if desired and scoop in pico de gallo and top with sliced avocado, or serve it all separately.