Set the 80/20 ground beef in a heavy pot over medium-high heat, about 7 on a 10-dial. Press it into one layer and leave it untouched for 2 minutes. Then break it into 3/4-inch crumbles and cook for 4 minutes. Add the diced yellow onion, carrots and celery. Stir from the bottom every minute for 3 minutes. Add the minced garlic for the final 30 seconds. The beef should show deep brown edges while the vegetables look glossy and slightly softened. The largest crumbles should reach 160°F. You'll hear the steady sizzle quiet as moisture cooks away. The garlic should smell toasted but not sharp. Stop too early and the meat steams once broth enters. Brown deeply before adding liquid because fond gives the broth its burger flavor.

Reduce the heat to medium, about 5 on a 10-dial. Add the unsalted butter and let it melt for 30 seconds. Sprinkle in the all-purpose flour and stir constantly for 60 seconds. Slowly pour in 2 cups of low-sodium beef broth over 2 minutes while scraping the bottom. Then add the remaining broth, Yukon Gold potato cubes, yellow mustard, Worcestershire sauce, smoked paprika, kosher salt and black pepper. The liquid should shift from clear brown to lightly opaque with no pale flour pockets. You'll smell toasted butter and beef while the bottom releases cleanly. The potato cubes should stay distinct and unevenly suspended around the crumbles. Pour the broth too fast and the base forms stubborn lumps. Add it gradually because smooth starch dispersion keeps the Creamy Cheeseburger Potato Soup Recipe velvety.

Raise the pot to medium-high heat, about 7 on a 10-dial, just until the broth reaches 190°F. Then lower it to medium-low, about 4 on the dial. Keep a gentle simmer for 12 to 15 minutes. Stir with broad bottom-to-top strokes every 3 minutes so the potatoes move without breaking. Test one cube at minute 12 by pressing it against the pot side. The potato should split under light pressure while keeping its squared edges. Small bubbles should rise mainly around the pot's perimeter. Meanwhile the broth will coat the beef crumbles instead of running off them. Go past 18 minutes and the potatoes can collapse into a gluey base. Hold the gentle simmer because controlled starch release thickens without turning pasty.

Lower the heat to low, about 3 on a 10-dial, and pour in the whole milk and heavy cream. Stir for 2 minutes until the broth reaches 175°F. Add the freshly shredded sharp cheddar in four handfuls over 3 minutes. Stir each handful in a slow figure-eight before adding the next. Remove the pot from heat and fold in the sour cream until no white streaks remain. The soup should turn creamy orange-gold while the cheddar disappears into a glossy coating around each potato cube. You'll smell warm dairy and mustard rather than scorched cheese. (I boiled my first batch, the cheese turned grainy. Low heat fixed it.) Let it pass 185°F and the dairy may split. Melt slowly because gentle heat keeps the fat emulsified.

Keep the pot off the heat and let the soup rest for 5 minutes until it settles near 165°F. Stir once from the bottom and ladle one generous portion into a warm white ceramic bowl. Scatter one-quarter of the crumbled thick-cut bacon across the center. Add 1 tablespoon chopped dill pickles slightly off-center and finish with one-quarter of the sliced scallions. The final bowl should look thick but spoonable with visible potato cubes and irregular beef crumbles. The cheddar broth should show orange-gold swirls and a few darker beef streaks. Crisp bacon adds rough edges while pickles add bright green flecks. Serve too soon and the toppings sink into a loose broth. Rest briefly because cooling lets the starch and cheese finish setting.