Peel and chop about 2.5 pounds of Yukon Gold potatoes into even half-inch cubes. Give them a quick rinse under cold water to wash away the extra starch. This helps you avoid that gluey texture that sometimes happens in blended soups. Set them aside.

In a large pot or Dutch oven, melt four tablespoons of unsalted butter over medium heat. Add one finely chopped yellow onion and let it soften for about five to seven minutes. The goal is translucent, not browned. Once the onion smells sweet and mellow, stir in the minced garlic and cook for another minute. Keep an eye on the garlic. Burned garlic can ruin the base.

Sprinkle in a quarter cup of all-purpose flour. Stir constantly for a couple of minutes. This thickens the soup and gives it that smooth, rich consistency later. It should smell a bit nutty and look like a paste. You’re not looking for color here, just a quick cook-off of the raw flour.

Pour in four cups of low-sodium broth slowly, whisking as you go. Scrape the bottom of the pot to catch all the flavor stuck there. Once everything is smooth, add the cubed potatoes. Bring the mixture to a gentle simmer. Cover and cook for fifteen to twenty minutes until the potatoes are fork-tender.

Use an immersion blender to partially blend the soup. Just a few pulses will do. You want a balance of creamy base with some potato pieces left for texture. If you’re using a regular blender, blend only half of the soup and return it to the pot. Be careful with hot liquids. Let the steam escape and never overfill the blender.

Lower the heat. Slowly stir in two cups of whole milk and, if you're using it, half a cup of heavy cream. Add the chopped parsley, chives, and thyme. Let everything heat through gently for about five minutes. Avoid boiling at this stage to keep the cream from curdling.

Turn off the heat. Add the freshly shredded sharp cheddar one handful at a time, stirring constantly until each addition melts completely. This keeps the cheese from becoming gritty or oily.

Add salt and freshly ground black pepper, adjusting slowly. If you like a bit of warmth, a pinch of cayenne or smoked paprika does wonders. Stir well and taste again before serving.

Ladle the soup into bowls and add your favorite toppings. Crumbled bacon, a sprinkle of extra cheddar, a dollop of sour cream, or a few crunchy croutons can all elevate the experience.