Chicken Spaghetti Casserole

1 (10.5 oz) can cream of mushroom soup

1 cup chicken broth

½ cup sour cream

4 oz Velveeta, cubed

1½ cups shredded cheddar cheese, divided

½ tsp garlic powder

½ tsp onion powder

½ tsp black pepper

1 (4 oz) can diced green chiles (optional for a mild kick)

1 cup frozen peas or mixed vegetables (optional)

¼ cup grated Parmesan cheese (for topping)