Spray slow cooker with nonstick spray and add potatoes
Heat skillet over medium-high heat
Dice bacon into small pieces and add to pan
Let bacon cook until it starts to brown and adds fat to the pan.
Thinly slice onions and add to pan
Cook, stirring occasionally until bacon is crisp and onions are lightly browned
Sprinkle in flour and stir to coat bacon and onions evenly
Slowly stir in broth and bring to low boil for about 4-5 minutes until it starts to reduce and thicken
Add cream and seasonings and let the mixture simmer for about 2-3 additional minutes
Remove skillet from heat and stir in about 8 ounces of the shredded cheese
When mixed well, carefully pour cheese mixture over potatoes and stir to coat evenly
Chop butter into several pieces and place on top
Top the potatoes with remaining cheese, cover, and cook for 3-4 hours on high or 5-7 hours on low