Loaded Mashed Potato Casserole

Bahan-bahan (6 porsi)

• 2 ½ lbs russet potatoes (peeled and cut into 1/2" cubes)
• 1 tsp salt (or to taste)
• 3/4 cup milk ((whole or 2% milk))
• 8 Tbsp unsalted butter
• ¼ cup sour cream
• 8 oz Colby Jack cheese (freshly shredded)
• 8 oz bacon (chopped)
• 2 Tbsp green onion or chives (to garnish)