Line a 6 quart slow cooker with foil and spray with non-stick spray. The foil adds to easy clean up, too.
Wash, dry, and prepare the potatoes. Cut potatoes in half, larger ones in quarters.
Dice 1/2 medium onion
Mince 2 cloves of garlic
Reserve 1/2 cup of the cheese for later. Also, reserve one tablespoon turkey bacon pieces for later. In the bottom of the slow cooker: Add half of the following for first layer: potatoes, cheese, garlic, cooked bacon, onions, and Everything But Salt seasoning. I omitted the salt for personal reasons. Repeat this for the next layer.
Fold in sides of aluminum foil around potatoes. Cover and cook on low until potatoes are tender, 2 to 3 hours.
Once the potatoes are tender and cooked through, top with the 1/2 cup reserved cheese, cover again and let melt. Once the cheese is melted, garnish with reserved turkey bacon pieces and sliced green onions and serve. Top with sour cream, if desired.