Trim off the ends of the yuca root using a sharp knife, then cut the root widthwise into three or four pieces.
Set each piece of yuca cut side up. Starting at the top and working in one fluid motion, slice the waxy exterior brown skin and interior pink layer from the yuca. Repeat with the remaining pieces.
Rinse the skinned yuca root under cool running water to remove any dirt or residue that might have transferred during trimming, then dice the flesh into 1” chunks.
Place the diced yuca and smashed garlic cloves into a sauce pan, along with 1 tsp salt. Add enough water or broth to cover the yuca by about an inch. Place the sauce pan over high and heat until the water boils. Reduce the heat to medium high and continue to boil until the yuca is soft and you can easily mash the flesh with the tines of a fork, about 20 minutes.
Drain the liquid and return the yuca and garlic to the pot. Alternatively, transfer the yuca and garlic to the bowl of a stand mixer.
Add the melted ghee and pepper to the pot or bowl. Using a hand mixer or the paddle attachment on your stand mixer, beat until the consistency is smooth and the yuca mash is light in color and fluffy in texture. Taste for seasoning, and add additional salt and pepper to taste. Serve warm. Yuca mash keeps in the fridge for up to 3 days, and reheats well in the microwave.