1/2 cup (1 stick) unsalted butter
1 medium onion, thinly sliced
3 leeks, rinsed well, and sliced
3 stalks of celery, sliced
1 pound Yukon gold potatoes, cut into-1-inch chunks
3 tablespoons olive oil
3 cans (14.5 ounces each) chicken broth
1 teaspoon salt
1/4 teaspoon pepper
small sourdough rounds (for bread bowls), shredded white cheddar cheese (I used Kerrygold Irish cheese), crumbled cooked bacon, and chopped scallions, for serving
Preheat oven to 400 degrees. On a rimmed baking sheet, toss potatoes with olive oil and season with salt and pepper to taste. Roast for 30 minutes.
In a large soup pot, melt butter over low heat; stir in the onion, leeks, and celery. Cover and cook 20 minutes. Stir in broth, 2/3 of the potato chunks, salt, and pepper and bring to a boil. Reduce heat, and simmer 30 minutes. In batches, using extreme caution, puree soup in a blender until smooth. Stir in remaining potato chunks. Serve in a bread bowl with desired toppings.