Over medium heat, melt butter in a saucepan or Dutch oven. Once melted, add the finely diced onion and cook until the onions are translucent, roughly 3-5 minutes.
Once onions are cooked, add flour and stir until onions are fully-coated. Cook for 15-30 seconds. Add chicken stock, heavy cream, garlic powder, salt, and pepper. Stir until well-combined. Allow ingredients to cook together and thicken for about 5-8 minutes.
Add in shredded cheddar cheese and beer and stir well. Cook until heated through and uniformly melted and smooth, roughly 2-4 minutes. If you want the soup to be thinner, add more cream.
Serve in a bowl topped with chopped bacon and chives (either fresh or freeze-dried). Enjoy!
