Crisp the bacon: Cook the chopped bacon in a large Dutch oven over medium heat for 7 to 8 minutes, stirring occasionally, until fully crisp and no soft pink pieces remain. Lift it out with a slotted spoon onto a paper towel-lined plate and leave about 2 tablespoons of the drippings in the pot.

Soften the onion: Add the diced onion to the bacon drippings and cook 5 to 6 minutes over medium heat, until translucent and just starting to color. Stir in the garlic and cook 30 seconds, then add the butter and let it melt.

Make the roux: Sprinkle the flour over everything and whisk constantly for 1 full minute. It will look like a thick paste, and that minute is what cooks off the raw flour taste.

Add the broth and potatoes: Slowly pour in the chicken broth while whisking, scraping the bottom of the pot as you go. Add the cubed potatoes, salt, and pepper. Bring to a boil, then reduce the heat, cover, and simmer 18 to 20 minutes, until a fork slides into a potato cube with no resistance.

Mash right in the pot: Take the pot off the heat and mash about half the potatoes directly in the broth with a potato masher, leaving the rest in chunks. The soup will thicken noticeably as you go.

Stir in the dairy: Return the pot to low heat and stir in the half-and-half and sour cream until smooth. Keep it below a boil from this point on, since sour cream curdles if it gets too hot.

Melt in the cheddar: Add the shredded cheddar a handful at a time over low heat, stirring until each addition disappears before adding more. Taste and add more salt and pepper if it needs it.

Load up the bowls: Ladle the loaded baked potato soup into bowls and top each one with the crisp bacon, extra shredded cheddar, and sliced green onions.