Step 1

Peel and dice the potatoes. Place the Yukon gold potatoes in a large pot and cover with 3 to 4 inches of water; add a generous amount of kosher salt. Bring to a boil, then add the sweet potatoes after 5 minutes. Boil 10 to 15 minutes more until both types of potatoes are tender. Drain and reserve 1/2 cup of the water. Return the potatoes to the pot.

Step 2

In the pot, pour back the 1/2 cup water to potatoes. Add the grated garlic (you can grate it right in), milk, kosher salt, chopped chives, and fresh ground black pepper. Mash until the desired consistency is reached. Serve immediately.