Preheat oven to 350 degrees F. Spray a 8-inch square baking dish with cooking spray and set aside.
In a large skillet over medium heat, heat oil. Add ground beef, onion and jalapeno and cook, breaking up meat with a wooden spoon, for 5-6 minutes or until browned. Sprinkle in taco seasoning, salt, and pepper and stir for 1 minute. Drain and return to skillet.
Add cream cheese, beef broth, and ¼ cup salsa, stirring into beef until creamy and well blended. Simmer for 5 minutes until combined.
To assemble, spread ½ of the taco meat mixture on the bottom of the casserole dish. Sprinkle 1 cup of cheese, then place one of the low carb tortillas on top.
Repeat for the second layer. Top tortilla layer with remaining salsa and sprinkle with cheese. Bake for 25 minutes.
Sprinkle with green onion and/or cilantro and serve with sour cream and sliced jalapeño, if desired.