Preheat your oven to 350 degrees and grease a baking pan.

In a frying pan, melt the butter on medium heat. Put the chopped onion and garlic in the pan and cook them until they smell good and look clear.

Put the seafood mix in the pan and cook it until it is cooked just right. Be sure not to cook the seafood for too long, because it can get hard to chew.

In another bowl, stir together the cooked rice, mushroom soup, milk, and cheese. Add as much salt and pepper as you like.

Mix the cooked seafood with the rice until it's all mixed.

Pour the mixed ingredients into the greased baking pan and spread it out evenly.

If you want, you can put bread crumbs on top of the casserole to make it crispy.

Put foil over the dish and cook it in the oven for 25-30 minutes until it's hot and bubbly.

After baking, take off the foil and cook under the broiler for 2-3 more minutes to make the top brown.

Heat it and savor the tasty flavors of the Seven Seas Casserole.