Caldo verde (Portuguese kale and potato soup)

Name: Caldo verde (Portuguese kale and potato soup)
Prep time: 15 min
Cook time: 45 min
Total time: 1 h
Cuisine: Portuguese
Ingredients: 4 tbsp extra-virgin olive oil, plus more to serve; 1 large onion, chopped; 3 garlic cloves, sliced; 1 kg floury potatoes, peeled and cut into 3 cm chunks; 2 l water; 2 tsp fine salt, plus more to taste; 150 g chouriço or cured Spanish chorizo, in one piece; 300 g couve galega, collard greens or kale, weighed after removing the thick stems

Portugal's green broth. A silky potato and onion base, thread-thin greens cooked for just a few minutes, slices of smoky chouriço and a last thread of good olive oil.

By the Soupmap Culinary Team

Prep: 15 min
Cook: 45 min
Total: 1 hr
Effort: Easy
Serves: 6

Broth richness 4/10

Spice 2/10

Comfort 7/10

Ratings by the Soupmap Culinary Team, not readers.

Photo: Mateus Hidalgo, CC BY-SA 2.5 br, via Wikimedia Commons

Caldo verde means "green broth", and it is about as plain as a soup gets: potatoes and onion simmered in water and puréed, a tangle of finely shredded greens, a few slices of smoky sausage and a thread of olive oil. It comes from the Minho, in the north-west of Portugal, and is now eaten all over the country.

What makes it is the knife work. The greens, traditionally couve galega (a tall, loose-leaved Portuguese cabbage, close to collard greens), are cut into threads so fine that they cook in a few minutes and swirl through the soup instead of sitting in it as heavy leaves. In Portugal you can buy them ready-shredded; at home, a sharp knife and a tightly rolled stack of leaves get you there.

The sausage is chouriço, a Portuguese cured pork sausage seasoned with garlic and paprika, simmered whole in the soup so it flavours the broth before it's sliced.

The usual mistake is treating the greens like any other vegetable and stewing them. A few minutes is enough: they should stay bright green and keep a little chew against the smooth potato. In Portugal it's often eaten with broa, a dense, crusty loaf made partly with maize flour.

Ingredients

Soup

4 tbsp extra-virgin olive oil, plus more to serve
1 large onion, chopped
3 garlic cloves, sliced
1 kg floury potatoes, peeled and cut into 3 cm chunks
2 l water
2 tsp fine salt, plus more to taste
150 g chouriço or cured Spanish chorizo, in one piece

Greens

300 g couve galega, collard greens or kale, weighed after removing the thick stems

Method

Cook the potatoes

Warm 2 tbsp of the olive oil in a large pot (at least 5 l) over medium-low heat. Add the onion and garlic and cook gently, stirring now and then, until soft and translucent but not browned, 8–10 minutes.
Add the potatoes, water and salt and bring to a boil over high heat. Add the whole piece of chouriço, lower the heat and simmer, partly covered.
After 15 minutes, lift out the chouriço and set it aside to cool. Keep simmering the potatoes until they break apart when pressed against the side of the pot, 5–10 minutes more.

Shred the greens

While the potatoes cook, strip the leaves from the thick central stems. Stack 5 or 6 leaves, roll them up tightly into a cigar and slice across as thinly as you possibly can, 1–2 mm, to get fine threads. Repeat with the rest, then wash the threads in a large bowl of cold water and drain well.
Slice the cooled chouriço into thin rounds, about 3 mm thick.

Purée and finish

Take the pot off the heat and purée until completely smooth with a stick blender, or mash hard with a potato masher for a more rustic soup. If you use a jug blender, work in batches, fill it no more than half full and hold the lid down with a folded cloth: hot soup expands and can force the lid off. Stir in another 2 tbsp olive oil.
Return the pot to medium heat and bring the soup back to a simmer, stirring so it doesn't catch on the bottom. Add the greens, stir them through and simmer uncovered until bright green and tender but still slightly chewy, 3–5 minutes (curly kale may need 5–6 minutes). If the soup seems too thick, loosen it with a little hot water; it should be about as thick as single cream.
Add the chouriço slices for the last minute to warm through. Taste for salt; it usually needs a little more. Ladle into bowls, making sure each gets a few slices of sausage, and finish with a thread of olive oil.

Swaps

Cooking for coeliac disease or an allergy? Check every label: the notes below say which ones matter.

Gluten-free

The soup itself contains no gluten, but some cured sausages include wheat as a filler, so choose a chouriço or chorizo labelled gluten-free.
Serve it with gluten-free bread rather than broa, which is usually made with wheat or rye flour as well as maize.

Plant-based

Leave out the chouriço and finish each bowl with extra olive oil and a small pinch of smoked paprika, as in Variations; everything else is already vegan. You lose the smoke and some richness, but the potato and greens carry it.
Plant-based chorizo can stand in for the sausage. Warm the slices through in the last minute only, and check the label if you also need it gluten-free, as many are made with wheat gluten.

High-protein

Stir 2 drained 400 g tins of white or kidney beans in with the greens: about 6 g more protein a bowl, on top of the roughly 10 g the soup has as written.
Double the chouriço to 300 g: about 6 g more a bowl, but also more salt and fat, so go easy on the salt in the base.
Top each bowl with a poached egg for about 6 g more.

Tips

Use floury potatoes. Varieties sold for mashing or baking break down into a smooth, creamy base with no cream needed. Waxy salad potatoes give a thinner, less creamy soup.
Shred finer than you think. Thread-thin greens cook in minutes and stay bright. Wider ribbons need longer, turn dull olive green and feel stringy.
Substitutes for couve galega: collard greens are the closest match, then cavolo nero (Tuscan black kale) or curly kale; spring greens also work. Avoid spinach, which collapses to nothing.
Choose cured sausage. Portuguese chouriço is ideal; cured Spanish chorizo is the easiest substitute. Use the firm, ready-to-eat kind for slicing, not soft fresh chorizo meant for frying.
Finish with your best oil. The raw olive oil on top is part of the dish, not a garnish, so this is the place for a fruity extra-virgin.

Make ahead and storage

The puréed potato base keeps for 3 days in the fridge or 3 months in the freezer. Add the greens only when you reheat it, so they stay green.
Leftovers with the greens in keep for 2 days in the fridge; they'll lose some colour but taste fine. Reheat until steaming throughout.

Variations

Vegan: leave out the chouriço and finish each bowl with extra olive oil and a small pinch of smoked paprika. Not traditional, but it echoes the sausage.
Gluten-free or dairy-free: the soup itself contains neither, but some cured sausages include wheat or milk ingredients, so check the label on yours.

Reviews & cooks' tips

Reviews and tips from people who've cooked this appear here.