Place diced bacon in a large pot over medium heat and cook until crisp, then remove bacon and set aside, leaving drippings in the pot. Look for bubbling fat and browned bacon pieces in about 6–8 minutes.

Sauté the diced onion in the reserved bacon drippings for 4 minutes, stirring now and then, until softened. Add the minced garlic and cook 1 minute, just until fragrant.

Add chicken broth and cubed red potatoes with skins (skins on) to the pot and bring to a gentle simmer. Simmer for 18–20 minutes, stirring occasionally, until potatoes are very tender and break apart easily when pressed.

Mash some of the potatoes in the pot to thicken the soup while keeping it chunky. Stop mashing once you get the rustic texture you want.

Stir in heavy cream and sour cream, then reduce heat to medium-low. Add shredded cheddar and stir until fully melted and the soup looks smooth and creamy.

Season with salt and black pepper, stirring to combine, then stir in fresh dill. Taste and adjust seasoning if needed, using the dill as the last flavor addition.

Ladle soup into bowls and top with reserved bacon, sliced green onions, and extra sour cream if desired. Serve hot so the cheese stays creamy.