Prepare the potatoes: Place the peeled and cubed potatoes in a large pot. Cover them with cold water by at least 2.5cm (1 inch). Add a generous pinch of salt (about 1 tsp or 5g) to the water.

Boil the potatoes: Bring the water to a rolling boil over high heat. Once boiling, reduce the heat to medium and simmer for 15-20 minutes, or until the potatoes are fork-tender. They should be easily pierced with a fork or knife with no resistance.

Drain and dry the potatoes: Once tender, carefully drain the potatoes in a colander. Return the drained potatoes to the hot, empty pot and let them sit over low heat for 1-2 minutes, shaking the pot occasionally. This helps to evaporate any excess moisture, resulting in fluffier mash.

Cook the bacon: While the potatoes are draining, cook the diced bacon in a separate skillet over medium heat. Cook until the bacon is crispy and golden brown, stirring occasionally. This usually takes about 8-10 minutes.

Drain the bacon: Once crispy, use a slotted spoon to transfer the cooked bacon to a plate lined with paper towels to drain off excess grease. Reserve about 1 tablespoon (15ml) of the rendered bacon fat in the skillet if desired for extra flavor, or discard the rest.

Mash the potatoes: Add the butter (120g or 1/2 cup) to the hot, dry potatoes in the pot. Allow the butter to melt for a minute, then begin mashing the potatoes with a potato masher or a sturdy fork until mostly smooth. For a smoother texture, you can use a potato ricer or food mill.

Incorporate milk and seasonings: Gradually add the warmed milk (240ml or 1 cup) to the mashed potatoes, mixing until you reach your desired consistency. Start with about half the milk and add more as needed. Stir in salt and freshly ground black pepper to taste.

Add cheese and bacon: Stir in most of the shredded cheddar cheese (about 150g or 1.5 cups), most of the crispy bacon (reserving some for garnish), and about half of the sliced green onions (25g or 1/4 cup) into the mashed potatoes. Mix until the cheese is melted and everything is well combined.

Serve: Transfer the loaded mashed potatoes to a serving dish. Garnish with the remaining shredded cheddar cheese, crispy bacon bits, and sliced green onions. Serve immediately.