Add thawed green beans to slow cooker.

Combine the cream of mushroom soup, half and half, parmesan cheese, garlic, seasonings, and just half of the fried onions. Stir well and add the mixture into the slow cooker on top of the green beans.

Fold everything together until the green beans are coated. Spread it all out into an even layer in the slow cooker.

Place lid on top and cook on the low setting for 3-4 hours or the high setting for 2 hours, until green beans are tender.

Stir the casserole well. Sprinkle the remaining fried onions. Serve immediately.