Line plate with paper towels and have near the stove. In a large pot or Dutch oven, cook the bacon over medium heat for 5 to 7 minutes, stirring occasionally, until crispy. Use a slotted spoon to transfer the bacon to the paper towels to drain, leaving the bacon fat in the pot.
In the same pot, combine the garlic, chopped scallions, and flour.
Whisk over medium-low heat for 2 minutes to make a roux, until the mixture is golden and smooth.
Stir in the heavy cream, chicken broth, milk, adobo seasoning, and salt and pepper to taste.
Add the potatoes and more chicken broth, if needed, to cover the potatoes. Cook, uncovered, for 20 minutes, stirring occasionally, until the potatoes are fork-tender. Stir in the Cheddar, reduce the heat to low, and simmer for 15 minutes, stirring frequently, until the cheese is melted.
Ladle the hot soup into bowls and serve with sour cream, Cheddar, sliced scallions, and the bacon sprinkled over the top.