Heat your oven to 375°F and grease a 9x13-inch baking dish.
In a big bowl, stir together the chicken, taco seasoning, sour cream, cheddar and green chiles until it looks creamy and well mixed.
Tear or trim the tortillas so they fit the dish.
Chop the Velveeta into chunks and put them in a skillet with the Rotel. Cook on medium-low, stirring often, until it's fully melted and smooth.
Spread a thin layer of queso on the bottom of the dish. Add a layer of tortillas, then half the chicken mixture, then more queso.
Repeat the layers until everything is used up. Finish with a generous pour of queso on top.
Bake at 375°F for 25 to 30 minutes, until it's bubbling at the edges and hot all the way through.
Let it sit for 5 to 10 minutes before cutting.