Place cheese in a 2-quart microwave-safe casserole dish; cook in microwave until mostly melted, 1 to 2 minutes. Stir in chicken soup, wild rice, broccoli, chopped onion, celery, hot sauce, and black pepper.
Microwave until fully cooked and bubbling, 12 to 14 minutes, rotating halfway through cooking. Sprinkle French-fried onions over casserole; cook for 1 more minute.