Preheat oven to 350°F (175°C). Lightly grease a 9x13-inch baking dish.
In a large skillet, cook ground sausage over medium heat until browned and fully cooked. Drain excess fat if necessary.
In a large mixing bowl, combine cream of chicken soup, cream of mushroom soup, Rotel, and sour cream. Stir in the cooked sausage and 1 cup of shredded cheese.
Spoon the sausage mixture evenly into the center of each tortilla. Roll up and place seam-side down in the prepared baking dish.
In a small saucepan, melt butter over medium heat. Stir in flour to form a roux. Slowly whisk in milk and cook until thickened. Season with salt and pepper.
Pour the creamy sauce evenly over the enchiladas. Sprinkle the remaining 1/2 cup of cheese on top.
Bake for 25–30 minutes until bubbly and golden. Garnish with parsley or green onions if desired. Serve warm.