Season and cook chicken as desired. Cool and dice.
Cook spaghetti according to package directions.
Saute chopped onion and red pepper in butter. Add Rotel tomatoes and worchestershire sauce. Simmer gently for 2-3 minutes.
Add the cheese and stir until melted. Add the diced chicken.
Mix all ingredients together with the cooked spaghetti.
Place in a greased 9x13 casserole dish and bake at 350 degrees for 20 minutes or until heated thoroughly and bubbly.