Add potatoes, chicken stock, bacon, and onion powder to the slow cooker. Cover with the lid.
Cook on LOW for 7-8 hours.
Once the potatoes have cooked, in a small sauce pan add the butter. Once the butter has melted, whisk the flour in to fully combine.
Slowly add the evaporated milk, whisking constantly. Add in the salt and pepper. Continue to cook over low heat, stirring constantly until it thickens. Remove from heat.
Pour into the potatoes and stir to combine.
Add in the greek yogurt and shredded cheese. Stir until all of the cheese has melted and it is mixed completely.