Cook the spaghetti: Boil the spaghetti in salted water until just al dente. Drain and set aside.
Preheat oven: Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish.
Mix the sauce: In a large mixing bowl, combine the cream of mushroom soup, cream of chicken soup, chicken broth, diced tomatoes with green chilies, green pepper, onion, and seasonings. Stir until well blended.
Add chicken and spaghetti: Add the shredded chicken, cooked spaghetti, and 1 ½ cups of shredded cheese to the sauce mixture. Toss everything together until evenly coated.
Transfer to baking dish:Pour the mixture into the prepared baking dish and spread evenly.
Top and bake: Sprinkle the remaining ½ cup cheese over the top. Bake uncovered for 35–40 minutes, or until bubbly and golden on top.
Garnish and serve: Sprinkle with a pinch of paprika and chopped parsley if desired. Serve warm!