Start by chopping and cooking the bacon in a cast iron skillet over medium heat. Once it's nice and crispy, transfer it to a plate lined with paper towels. Keep about 1–2 tablespoons of bacon grease in the skillet for extra flavor.
Season your chicken thighs with salt and pepper on both sides. Place them in the hot skillet and sear for about 4-5 minutes per side until golden and cooked through. Remove and set aside to rest for a few minutes, then cut into bite-sized pieces.
In the same skillet, add diced onions, garlic, and jalapeños. Let them cook in the bacon grease until softened and lightly golden. This gives the veggies a great depth of flavor and takes the edge off the raw jalapeño heat.
Lower the heat and add cream cheese and sour cream to the skillet. Stir slowly until they melt into a smooth, creamy mixture. Toss in one-third of the shredded Colby Jack and stir until the cheese melts into the sauce.
Return the cooked chicken and bacon to the skillet and stir everything together so it’s coated in that delicious cheese sauce. Sprinkle the remaining Colby Jack cheese evenly over the top. Garnish with sliced jalapeños and green onions if you like.
Transfer the skillet to a preheated oven at 375°F and bake for 25 minutes. Then, switch to broil for 3–4 minutes until the top gets bubbly and lightly browned. Take it out and let it sit for a couple of minutes before serving.