Add cubed potatoes and fresh garlic cloves to a large stockpot. Pour chicken stock in, and set to medium-high heat. Allow to come to a boil, then cover, boiling for 15-20 minutes, or until the potatoes can be easily pierced with a fork.
Drain the cooked potatoes and garlic in a colander, then return back to the pot. Adjust the burner to low heat.
I usually mash potatoes directly in the pot with a potato masher, because I dont mind a few small lumps. But, if you want them perfectly smooth, I recommend running the hot potatoes and cooked garlic cloves through a potato ricer after draining. Then, return the riced potatoes to the pot to finish up.
Gently mash the potatoes with a potato masher to begin to break them up. Add cream cheese, butter, salt, onion powder, and garlic powder. Continue to mash until the potatoes are creamy and minimal lumps remain.
Remove from heat, add sour cream and chives. Whip to combine. Serve warm.