Make the Pico de Gallo. Combine the tomato, red onion, lime juice, and cilantro in a medium mixing bowl. Stir and season to taste with salt and pepper. Set aside.
Preheat Blackstone griddle to medium heat. Drizzle vegetable oil then add the ground beef. Season with the packet of fajita seasoning and cook until browned. Add the black beans and a large scoop of the Pico de Gallo prepared earlier. Stir together until the beans are completely heated through.
Turn the griddle down to low heat. Layer the tortilla chips, shredded cheese, pickled jalapenos, and black bean ground beef mix directly onto the griddle. Cover with a large basting dome or the griddle hood and let melt for 10 minutes.
Remove the nachos from the griddle and set them on a large serving platter. Top with sour cream, sliced avocado, and Pico de Gallo. Serve immediately.