In a large pot, melt the butter over medium heat.

Add in the flour and whisk for 1 minutes to create a roux  (it will begin to brown a bit). Whisk in milk little by little.  Whisk constantly until it begins to thicken (about 3 minutes).

Stir in potatoes, minced onion and garlic.  Let it come to a boil then reduce the heat and simmer until potatoes are fork tender (about 20 minutes).

Add the sour cream, cheese, salt and pepper and stir until combined.  Taste and adjust the seasoning if necessary. You can also add more milk if your soup is too thick.

Serve in bowls and add any toppings you like! Enjoy!