Potato soup can be bland or artery-clogging. This is neither. The flavor comes from roasting the potatoes, onions and garlic to a deep golden brown before transforming them into a smooth -- or chunky -- purée. It's delicious on its own, but even better with a few garnishes. —Rivertree kitchen
medium russet potatoes, scrubbed
large cloves garlic, unpeeled
salt and pepper (be generous)
fresh thyme leaves, or 1 tsp. dried
chicken or vegetable stock
garnishes: cooked cubed ham or crumbled bacon, grated sharp cheddar, sliced scallions, sour cream or Greek yogurt
Heat the oven to 450 degrees F. Peel the potatoes if desired (it's not necessary), and cut into 1-inch cubes. Peel the onion and cut into large wedges.
Heap the potatoes, onion, and unpeeled garlic cloves on a large baking sheet. Drizzle with the olive oil and toss with your hands to coat well. Spread everything out as evenly as possible. Sprinkle liberally with salt (a good teaspoonful) and pepper, the thyme. Roast for 20 minutes, on whichever level will allow for the most browning (in my gas oven, it's the bottom rack).
Leaving the oven on, take out the baking sheet. If the garlic cloves and onions are browned and tender enough for you, take them out and set aside. Toss the potatoes well and roast for another 10-15 minutes until everything is well-browned and tender.
Scrape the potatoes into a large stockpot. Carefully pour 1/2 cup or so of stock on the baking sheet and scrape with a fork to get all the browned bits. Pour into the stockpot. Add the reserved onions, if you pulled them out earlier. Pour about 4 cups of stock in the pot. Squeeze the garlic out of their skins onto a plate or cutting board, and mash with a fork. Stir into the pot. Place on high heat and bring to a boil. Reduce the heat to medium-low and simmer for about 15 minutes. Taste and adjust the seasoning if necessary.
Using an immersion blender, purée the soup so that it's thick but there are still chunks of potato and onion. Add more stock if needed to reach desired consistency. If you'd like a smoother soup, purée it in batches in a food processor until silky. Serve hot, garnished as you like.