It's not the prettiest vegetable in the garden, but celery root, aka celeriac, is brimming with nutrients.

The high-fiber, knobby-looking veggie is an excellent source of potassium (controls heart rate and blood pressure) and vitamins A and C (powerful antioxidants). It's no surprise celery root has a distinct celery flavor and, because it cooks up tender when boiled, it makes an excellent addition to everyday mashes. I made these creamy, celery root-spiked spuds for my kids, and they devoured them!

1 1/2 pounds Russet potatoes (about 2 large), peeled and cut into 2-inch cubes

1 pound Yukon Gold potatoes (about 4 medium), peeled and cut into 2-inch cubes

1 celery root (celeriac), about 1 pound, peeled, cut into 1-inch cubes

Place both potato varieties, celery root and garlic in a large stock pot and add enough water to cover by about 2 inches. Set the pan over high heat, bring to a boil, reduce the heat to medium-high, and simmer until potatoes and celery root are fork-tender, about 25 to 30 minutes.

Drain, reserving 1/2 cup of the cooking liquid. Return the potatoes, celery root and garlic to the pot and add the sour cream, mustard and oil. Using a potato masher, mash the vegetables until you reach the desired consistency (chunky or smooth), adding the reserved cooking liquid a little at a time if necessary to loosen the mixture. Season to taste with salt and pepper.

  Robin Miller is host of Quick Fix Meals, a nutritionist and author of 10 cookbooks, including “Robin Takes 5” and “Robin Takes 5 for Busy Families.” She is the busy mom of two active boys. Her boys and great food are her passion. Check her out at www.robinmillercooks.com.