Prepare the Bacon: Preheat the oven to 400°F (200°C). Line a large baking sheet with parchment paper or foil. Lay the bacon slices in a single layer on the prepared sheet and bake for 15-20 minutes, or until crispy. Once done, carefully pour the bacon grease into a heatproof container and save it for the potato peels. Transfer the bacon to a paper towel-lined plate to drain, and once cool, crumble it. Set aside.
12 ounces bacon
Peel: While the bacon is baking, use a vegetable peeler to peel the yellow potatoes, making sure to save the peels. Place the peels in a large bowl and cover with cold water to keep them fresh.
3 pounds yellow potatoes
Quarter: After peeling, quarter the potatoes and place them in a large pot.
Boil: Cover the quartered potatoes with cold water and generously salt the water. Bring the pot to a boil over high heat, then reduce to medium heat and cook for 15-20 minutes, or until the potatoes are fork-tender. Drain the potatoes and set them aside.
Prep Peels: While the potatoes are boiling, drain the potato peels and pat them dry thoroughly with paper towels. Spread the peels out on a baking sheet, drizzle with the saved bacon grease, and toss to coat evenly.
Bake Peels: Bake at 400°F on the top rack for 10-15 minutes, or until golden and crispy. Season generously with salt while hot. Set aside to use as a garnish.
Mash the Potatoes: While the potatoes are still hot, mash them using a food mill, ricer, or potato masher until smooth and fluffy.
Season: In a microwave-safe bowl, combine the butter and minced garlic. Microwave in 20-30 second intervals for about 2 minutes, until the butter is hot and fragrant. Separately, microwave the milk for 2 minutes to warm it. Stir the garlic butter, warm milk, sour cream, 1 1/2 teaspoons of salt, black pepper, and onion powder into the mashed potatoes. Mix until everything is well combined and creamy. Gently fold in half of the shredded cheddar cheese, half of the crumbled bacon, and the sliced green onions. Taste and adjust seasoning if needed.
4 Tablespoons unsalted butter, 4-5 cloves garlic, finely minced, 1 cup milk, 1 cup sour cream, 1 1/2 teaspoons Morton kosher salt, plus more for water*, fresh ground black pepper, 2 teaspoons onion powder, 8 ounces cheddar cheese, shredded, 1/3 cup sliced green onions, plus more for garnishing
Transfer: Transfer the mashed potatoes to a large baking dish. Top with the remaining cheese and bacon.
Bake & Garnish: Bake at 400°F for 15-20 minutes, or until the top is lightly golden and the cheese is melted and bubbly. Remove the dish from the oven and garnish with the crispy potato peels and extra green onions.