1. Cook the potatoes
   • Pierce the potatoes multiple times with a fork.
   • Microwave them on high for 12–15 minutes, or until tender when pierced with a fork.
   • Let cool slightly, then halve the potatoes, scoop out the flesh, discard the skins, and cut the flesh into chunks.
2. Cook the bacon
   • Cook the bacon in a skillet over medium-high heat until it turns crispy.
   • Transfer the cooked bacon to a plate lined with paper towels to drain and cool.
   • Reserve up to 1 tablespoon of bacon fat from the pan (discard remaining fat).
   • Once bacon is cool, crumble it into small pieces.
3. Sauté aromatics & build a roux
   • In a large soup pot, melt the butter over medium-low heat.
   • Add the reserved bacon fat, minced garlic, and diced onion. Sauté ~2–3 minutes until the onion is soft and translucent.
   • Gradually whisk in the flour, stirring for about 1–2 minutes (this begins the thickening process and removes the raw flour taste).
4. Add liquids & simmer
   • Slowly whisk in the milk and half-and-half, stirring continuously until smooth.
   • Gradually pour in the chicken stock while whisking.
   • Bring the mixture to a light simmer.
   • Whisk in the salt, garlic salt, and black pepper.
   • Keep the soup at a light simmer, stirring occasionally, until it thickens slightly (about 5–7 minutes).
5. Incorporate cheeses, sour cream & bacon
   • Reserve ¼ cup of each of the cheeses and some crumbled bacon for garnishing (optional).
   • Stir the remaining cheeses, sour cream, and the rest of the crumbled bacon into the pot until melted and smooth.
   • Remove the pot from heat.
6. Add potato chunks & serve
   • Fold the potato chunks into the soup, breaking them slightly if you prefer a more blended texture or leaving them intact for chunkier soup.
   • Ladle into bowls and top with reserved cheese, bacon, and fresh chives. Serve hot.

Optional oven method for potatoes: Preheat your oven to 350 °F (about 175 °C). Bake the potatoes directly on the rack for ~45 minutes or until tender. Then proceed with peeling, mashing, etc., as above.