Add shredded chicken and season with taco seasoning.
Sauté until thoroughly mixed for 3-4 minutes. Using a slotted spoon remove onto a plate and keep warm.
For the nachos, arrange the tortilla chips in a single layer, overlapping slightly, on to a baking sheet pan. Spread the chicken evenly over the chips.
Sprinkle the cheeses evenly over the chicken and add tomato and onion on top.
Bake until the cheese is melted, 4-5 minutes.
Remove the nachos from the oven, then sprinkle with scallions and spreading the guacamole, sour cream, and lime wedges separately.