
Preheat the oven to 350 degree F. Grease a 3qt casserole dish and keep it aside.
Meanwhile, bring a large pot of salted water to boil, blanch the green beans for 3-5 minutes and transfer them to an ice bath to stop the cooking process. Set aside.
Over medium heat, add the condensed cream of mushroom soup and milk into a sauce pan or pot and bring to simmer. Stir in the spices; garlic powder, pepper, salt and paprika.
Bring the mixture to simmer and add the grated cheese. Stir constantly, until the cheese is completely melted.
Pour the saucy mixture over the blanched green beans. Toss together.
Transfer the green beans along with the cheesy sauce into the prepared casserole dish. Do not add the onions yet. Bake for 20 minutes until warm and bubbly around the edges.
Remove from the oven and add the fried onion on top and bake further for 5-7 minutes.
Allow to cool for a few minutes and serve warm.