Preheat the oven to 375°F (190°C).
In a large skillet over medium-high heat, add the olive oil and chicken strips.
Season with chili powder, cumin, garlic powder, salt, and pepper.
Cook for about 5-7 minutes or until the chicken is cooked through.
Remove the chicken from the skillet and set aside.
In the same skillet, add the sliced bell peppers and onion. (add oil, if needed)
Season with salt and pepper and cook for about 5 minutes until the vegetables are tender.
Spread the tortilla chips on a large baking sheet.
Top with the cooked chicken and sautéed vegetables.
Sprinkle the shredded cheese over the top of the nachos.
Bake in the preheated oven for about 10-12 minutes or until the cheese is melted and bubbly.
Remove from the oven and top with sliced jalapeños and chopped cilantro.
Serve the chicken fajita nachos with sour cream and guacamole on the side, if desired.