Peel and cube Yukon Gold potatoes into uniform ½-inch pieces. Rinse under cold water until water runs clear to remove excess starch. This step prevents gummy texture later. Pat dry and set aside.

Heat butter in a large pot or Dutch oven over medium heat until melted and foaming. Add chopped onion and cook for 6-8 minutes, stirring occasionally, until softened and translucent with no brown edges.

Add minced garlic and cook for 1-2 minutes, stirring constantly until fragrant. Watch carefully here – burnt garlic will make the whole soup bitter.

Sprinkle flour over the aromatics and stir continuously for 2-3 minutes. You want to cook out the raw flour taste and create a light golden roux that will thicken your soup perfectly.

Slowly whisk in broth, starting with just a splash to create a smooth paste, then gradually adding the rest. Scrape up any browned bits from the pot bottom. Bring to a gentle simmer.

Add rinsed potato cubes and stir well. Bring back to a simmer, then reduce heat to medium-low. Cover and cook for 18-22 minutes until potatoes are fork-tender but not falling apart.

Using an immersion blender, pulse 8-10 times until about half the soup is smooth while leaving plenty of potato chunks for texture. The goal is creamy with hearty pieces throughout.

Reduce heat to low and slowly stir in milk and cream. Add fresh herbs and heat gently for 3-4 minutes. Do not let it boil or the dairy will curdle.

Remove completely from heat. Add shredded cheese one small handful at a time, stirring until each addition melts completely before adding more. This prevents graininess. Taste and season with salt, pepper, and optional spices.