This simple, hearty chicken soup is built around a roasted whole chicken, everyday vegetables, and a trick with the potatoes that makes the broth thick and creamy without any cream at all. The ingredient list is short, the technique is straightforward, and the result is a deeply satisfying soup that tastes like you put in a lot more effort than you actually did. It reheats beautifully and freezes well, which makes it just as practical as it is delicious.
Pat the chicken dry, rub it all over with about 1 tablespoon of olive oil, and season generously with salt and pepper.
Roast for 1½ to 2 hours— figure roughly 20 minutes per pound — until a meat thermometer reads 165°F (74℃) in the thickest part of the thigh. Remove from the oven and let it cool enough to handle.
Wash the leeks
Leeks hide grit between their layers, so they need a proper wash.
Trim off the dark green tops and the root end, leaving the white and pale green parts.
Slice them in half lengthwise, then fan the layers open under cold running water, working from the top down so the grit flushes out rather than settling deeper. You can also slice them into half-moons first, then submerge in a bowl of cold water, swish them around, and let the sand sink to the bottom before lifting the leeks out.
Prep the vegetables
Dice the leeks, zucchini, carrots, and potatoes into roughly 3/4-inch chunks. Keeping everything a similar size means everything cooks evenly.
Sweat the vegetables
Heat the remaining 2 tablespoons of olive oil in a large heavy pot over medium-low heat. Add all the vegetables, stir to coat in the oil, cover the pot, and let them cook low and slow for 15 to 20 minutes
You are not browning anything here. Sweating draws out the vegetables' natural moisture and sweetness, and gently softens them. Lift the lid to stir every 5 minutes or so, and if anything starts to color, lower your heat. Test the potatoes. When they are soft, remove the pot from the heat.
Shred the chicken
Pull the meat from the cooked chicken. Discard the skin, but save every bit of juice that collected in the roasting pan — those drippings are liquid gold for this soup. Shred the meat into generous pieces.
Add broth and mash
Once the potatoes are soft, pour in the 8 cups of chicken broth.
Use a potato masher right in the pot to mash the vegetables — focus on the potatoes, which will dissolve into the broth and give the soup a thick, creamy body without any cream at all. Leave some texture; you are not going for a puree.
Add the chicken and simmer
Stir in the shredded chicken and all the reserved roasting juices. Bring the soup to a gentle simmer and let everything come together for about 10 minutes
Finish and serve
Taste and adjust salt and pepper as needed.
Just before serving, stir in a good handful of chopped fresh parsley (about half a bunch) and squeeze in the juice of the 1 lemon. The parsley and lemon brighten the whole bowl and balance the richness of the broth.