In the bowl of a large slow cooker, combine chicken, onion, broth, heavy cream, garlic powder, and oregano. Season with salt and pepper; cover and cook on high until chicken is cooked through, 3 to 3 ½ hours.
Stir in broccoli and noodles, cover and cook until pasta is tender, 20 to 30 minutes more.
Garnish with crushed Ritz, parsley and red pepper flakes before serving.
