Clean the potatoes and quarter them (leave the skin on).
Place the potatoes in a large pot and cover them with water. Bring to a boil and simmer for about 10-15 minutes until the potatoes are fork tender.
Drain the potatoes and then return them back to the pot.
Then add in the garlic, ranch seasoning, butter, salt and 1/2 a cup of the milk. Use an electric mixer to blend the potatoes until they are light and fluffy.
Add in the sour cream and Gradually add in the remaining milk until the mashed potatoes are the consistency that you prefer.
Preheat the oven to 350 degrees Fahrenheit and place the mashed potatoes in a 9X9 baking pan.
Then top the mashed potatoes with the shredded cheese, bacon and chives.
Cover with foil (slightly tent the foil so that it does not stick to the cheese) and bake for 10-15 minutes until the cheese is completely melted.