Step 1

Place white potatoes into the bottom of a saucepan, then sweet potatoes on top. Add 1 teaspoon salt. Barely cover potatoes with cold water. Bring to a boil, then reduce to simmer until potatoes are fork-tender but not falling apart.

Step 2

Drain potatoes. Remove sweet potatoes from the pan and place them into another bowl. Place white potatoes back into your original pan and let them dry while you mash the sweet potatoes. For this step, I put on exam gloves (which I always have in my kitchen) to remove the hot sweet potatoes.

Step 3

Mash the sweet potatoes your favorite way. (I use a ricer, but a potato masher or portable mixer is also good.)

Step 4

Start with about 2 tablespoons of warm milk. Add more, if needed, to make potatoes creamy and smooth but not runny. Season with salt and pepper to taste.

Step 5

Repeat steps 3 and 4 with the white potatoes. Again, start with about 2 tablespoons of milk. Add more milk, as needed, until the consistency matches your sweet potatoes.

Step 6

Plop mashed sweet potatoes back into the pan with mashed white potatoes. Make a couple of folds with a spoon to barely mix. Move to a serving dish being careful not to mix too much.