Heat up the oven and skillet. Preheat the broiler on high. Heat a cast iron skillet over medium/high heat.
Prepare the ingredients. Cut the tomatillos in half. Slice the Serrano and red Chile pepper into thin slices. (Seed them for less heat, however we suggest keeping the seeds in and adding more garlic cloves to balance the spicy flavor) Dice ½ the white onion, and thinly slice the other half. Cut the grape tomatoes in half. Chop cilantro. Juice the orange and limes into a small bowl. Shred the cheese into a bowl. Dice the avocado and refrigerate until ready to serve.
Prepare the salsa. Once the skillet is hot, add a dash of olive oil and swirl to coat the pan to prevent sticking. Next, add the tomatillos (with the cut side up) and sliced peppers to the pan. Cook for 6 minutes to allow the skin of the tomatillos and chile peppers to slightly char. Add a pinch of salt and pepper if desired.
Turn the tomatillos and peppers over, then add the diced onions, tomatoes, and garlic cloves. Cook for 4 more minutes. Use a slotted spoon to remove ingredients and add to a food processor or blender. *Keep the skillet over heat.*
Add the orange and lime juice, 1 tbsp olive oil, salt, pepper, cumin seeds, and 2 tbsp of chopped cilantro to the food processor. Puree until smooth. Remove 2 tbsp of salsa and set aside for the steak.
Add cubed steak to a bowl and toss with 2 tbsp of the salsa. Pour another swirl of olive oil in the skillet. Add the cubed steak and sear for 2 minutes. *Do not overcook the steak. It will not be fully cooked after a short sear but will finish coming to temp in the oven. This helps the steak to remain tender*. Remove from heat and set aside on a plate or cutting board.
Add a handful of chips to a large baking sheet. Just enough to cover the bottom of the sheet. Top with a thin layer of shredded cheese, ⅓ of the steak, and a couple spoonfuls of the salsa and pico de Gallo. Repeat layering chips, cheese, steak, salsa, and pico. *Don’t be afraid to pile this high! The goal is for each chip to have a bit of something on it rather than fighting over the cheesy top layer! *
Place nachos into the oven under the broiler and cook for 3 minutes. The cheese will melt quickly so be sure to watch to prevent any burning.
Top nachos with shredded lettuce and avocado, drizzle with sour cream and remaining sauce. Garnish with cilantro.