After washing, pierce the potatoes multiple times with a fork, then microwave them for 12 to 15 minutes, or until tender and let cool.
Once cool enough to handle, remove the skins, and cut into chunks.
Meanwhile, cook the bacon in a skillet over medium-high heat until crisp. Transfer to a paper towel-lined plate to drain and cool.
Once the bacon has cooled, crumble it into small pieces.
In a large pot, melt the butter over medium-low heat. Add the garlic and onion and cook for 2 to 3 minutes, or until the onion is tender.
Slowly whisk the flour into the pan and stir for 1 to 2 minutes.
Slowly whisk in the milk and half-and-half. Keep whisking until smooth.
Gradually add the chicken stock.
Bring to a light simmer and whisk in the salt, garlic powder and pepper. Keep at a light simmer until the mixture has thickened slightly, 5 to 7 minutes.
Stir in the cheeses bacon, and the sour cream. Reserving 2-3 slices of bacon and at least 1/4 cup of each cheese for the garnish.
Remove the pot from the heat.
Use a potato masher to break some of the potato chunks into smaller pieces or leave them chunky, if preferred.
Serve hot, topped with your favorite garnishes, like cheese, bacon, sour cream and chives.