Preheat the oven to 400°F. Spread the bacon on a rimmed baking sheet and place on the middle rack of a cold oven. Bake for 16-18 minutes until crispy. Remove and drain on paper towels.

While the bacon cooks, toss the chopped potatoes with 2-3 tablespoons of bacon grease on the same sheet. Season with salt and pepper. Roast for 20 minutes, stir, and bake for an additional 20 minutes, then stir again and bake for 15 minutes until golden and crispy.

Chop the cooked bacon into small pieces. Remove the potatoes from the oven, sprinkle generously with shredded cheese and bacon bits. Return to the oven for 2-3 minutes until cheese melts. Garnish with sliced green onions and serve hot.