INGREDIENTS:
3-4 cups good-quality chicken or vegetable stock
2 pounds Yukon gold potatoes, peeled (if desired) and diced
1 medium white or yellow onion, peeled and diced
4 tablespoons butter
1/3 cup all-purpose flour
1 (12-ounce) can 2% evaporated milk
1 cup shredded reduced-fat sharp cheddar cheese
1/2 cup plain low-fat Greek yogurt or low-fat sour cream
1 teaspoon Kosher salt, or more to taste
1/2 teaspoon freshly-cracked black pepper
optional toppings: thinly-sliced green onions or chives, extra shredded cheese, sour cream