Peel the yam and cut it into chunks.
In a large pot, bring 4 cups of water to a boil. Add a pinch of salt.
Add the yam chunks to the boiling water. Reduce heat and simmer for 20-30 minutes, or until the yam is tender and can be easily pierced with a fork.
Drain the cooked yam and return it to the pot. Add butter or coconut oil and mash the yam until smooth. Season with salt and pepper if desired.
Enjoy your meal!