Walnut-Parmesan Mashed Potatoes - Kosher.com

Ingredients

• 3 pounds (6-8 medium) Yukon Gold potatoes
• 2 tablespoons Gefen Olive Oil
• 1 large onion, halved and thinly sliced
• 1 cup milk
• 1 stick (1/2 cup) butter
• 1/4 cup Parmesan cheese
• 1 tablespoon salt, plus more to taste
• 1/2 cup finely chopped walnuts
• pepper, to taste