Preheat the oven to 350 degrees F (175 degrees C).
Place the processed cheese into a large microwave-safe bowl along with the cream of chicken soup. Heat on full power for 2 minutes, stirring occasionally, or until cheese is melted. Season with salt, pepper, and Cajun seasoning. Stir in the green beans. Pour into a 1 1/2 quart casserole dish, and sprinkle the French fried onions over the top.
Bake for about 20 minutes in the preheated oven, or until the top is crispy.