In a large cast iron skillet, fry bacon over medium heat. Remove from pan and set on a plate lined with paper towels to cool.
Drain off most of the bacon grease. Melt 2 tbsp butter in the pan.
Add the Brussel's Sprouts and onion to pan. Saute on medium high heat until the sprouts are slightly browned. Add in the garlic and saute for 1 more minute.
Stir in the heavy cream, salt and pepper and crumbled bacon. Bring to a low boil and reduce heat to very low. Let the cream thicken and reduce some.
Remove the pan from heat and stir in shredded cheddar cheese.