How to Make It
Peel potatoes, reserving about 1 cup large potato peels; discard remaining peels. Cut potatoes into 1/2-inch cubes, and set cubes aside. Heat olive oil in a Dutch oven over medium-high. Working in batches if needed, add potato peels to Dutch oven in a single layer, and cook until crispy, about 1 minute and 30 seconds per side. Transfer to a plate lined with paper towels; sprinkle with pepper and 1/4 teaspoon salt, and set aside.
Add bacon slices to Dutch oven, and cook over medium until crispy, 10 to 12 minutes. Transfer bacon to a plate lined with paper towels, reserving 3 tablespoons drippings in Dutch oven. Set bacon aside.
Add light green and white scallion slices and garlic to hot drippings, and cook over medium, stirring occasionally, until tender and lightly browned, about 3 minutes. Stir in potato cubes, milk, cream, and remaining 2 teaspoons salt. Increase heat to medium-high, and bring to a low boil. (Be careful not to let mixture curdle.) Reduce to heat to low, cover, and simmer until potatoes are tender, 15 to 20 minutes.
Process potato mixture with an immersion blender until smooth. (Or, working in batches, pour potato mixture into a blender. Secure lid on blender, and remove center piece to allow steam to escape. Place a clean towel over opening. Process until smooth, about 2 minutes. Return mixture to Dutch oven.) Stir in sour cream and Cheddar cheese until blended. Crumble bacon. Serve soup topped with crumbled bacon, sour cream, cheese, crispy potato skins, and darker green scallion slices.