Bake the Potatoes: Preheat your oven to 400°F (200°C). Place the scrubbed and poked Russet or Yukon Gold potatoes wrapped in foil on a baking sheet. Bake for about 45-60 minutes, or until the potatoes are tender when pierced with a fork. Once done, let them cool slightly, then unwrap and chop into bite-sized pieces.

Sauté the Vegetables: In the same pot with the remaining bacon grease, add the chopped onion. Sauté for 4-5 minutes until it becomes translucent. Add the minced garlic and cook for an additional 1-2 minutes, stirring frequently until fragrant.

Make the Roux: Sprinkle the flour over the sautéed onions and garlic, stirring to combine. Cook for about 1 minute to remove the raw flour taste.

Add the Liquid: Gradually whisk in the chicken stock (or vegetable stock), making sure to scrape up any bits stuck to the bottom of the pot. This will help thicken the soup. Bring the mixture to a simmer.

Combine with Potatoes: Gently fold in the chopped baked potatoes. Stir to combine and heat through.

Incorporate the Creams and Cheese: Reduce the heat to low and stir in the sour cream, milk, and heavy cream. Mix well to combine. Gradually stir in the cheddar cheese and sharp cheddar cheese until melted and the soup is creamy. Bring the soup to a simmer and season with salt and black pepper to taste. Turn the heat off just be careful not to bring the soup to a rapids boil so the cream doesn't separate and become grainy.

Serve: Ladle the soup into bowls and top with the crispy bacon and finely chopped green onions for garnish.

Enjoy! Serve hot and enjoy your delicious baked potato soup!

Tips: For an extra kick, you can add some hot sauce or cayenne pepper. You can also customize this soup by adding other toppings like crumbled bacon, more cheese, or even sour cream.