El puerro queda muy bien con la patata en la sopa.

Here quedar bien con means to go well with or to work well with.

So El puerro queda muy bien con la patata means that leek and potato are a good combination, especially in this dish.

This is a very common use of quedar in Spanish:

• Ese color te queda bien. = That colour suits you.
• El queso queda bien con el vino. = Cheese goes well with wine.

It does not mean to stay or to remain in this sentence.

Because the subject is El puerro, which is singular.

• El puerro queda muy bien... = The leek goes very well...
• Los puerros quedan muy bien... = Leeks go very well...

Even though la patata is also in the sentence, it is part of the phrase con la patata, not the subject.

Spanish often uses the definite article when talking about ingredients or foods in a general sense.

So:

• El puerro = leek, as an ingredient in general
• La patata = potato, as an ingredient in general

In English we often drop the article:

• Leek goes well with potato in soup.

But in Spanish, using the article here sounds natural:

• El puerro queda muy bien con la patata.

This is very common with food:

• El ajo va bien con el pescado.
• La cebolla combina bien con el tomate.

The singular is being used generically, to talk about potato as an ingredient, not one single potato.

Spanish often does this with foods:

• La manzana es saludable. = Apples are healthy / The apple is healthy as a food.
• El tomate combina bien con la albahaca. = Tomato goes well with basil.

If you said las patatas, it would sound more like actual individual potatoes or potatoes in a more specific countable sense. Here la patata is the most natural generic choice.

Yes, but patata is the standard and most usual word in most of Spain.

• In Spain: patata is the safer default.
• In many Latin American countries: papa is more common.

So for Peninsular Spanish, la patata is exactly what a learner should expect here.

It applies most naturally to the whole combination.

The idea is: Leek goes very well with potato in soup.

So the sentence is not mainly saying where the potato is; it is saying that when making soup, leek and potato are a good pairing.

That is why the sentence feels like a comment about cooking and flavour combinations, not just physical location.

Because that is a very natural place in Spanish for this kind of extra information.

The core idea is:

• El puerro queda muy bien con la patata.

Then en la sopa is added to specify the context:

• ...en la sopa = in soup / in a soup context

Putting it at the end sounds smooth and normal. Spanish often places this kind of phrase after the main statement.

Yes. Both are natural, but they are slightly different in feel.

• El puerro queda muy bien con la patata en la sopa.
• El puerro combina muy bien con la patata en la sopa.

Combinar bien con is a bit more directly about matching or combining. Quedar bien con is very idiomatic and common, and can sound a little more like works really well with.

For food, both are good Spanish.

It can sound like a general statement, especially because el puerro and la patata are being used generically.

So the meaning is something like: Leek goes very well with potato in soup.

However, en la sopa can also sound slightly contextual, depending on the conversation. For example, if people are discussing a particular soup recipe, it could refer to that context too.

If you wanted to make it clearly more general, you might also hear:

• El puerro queda muy bien con la patata en las sopas.
• El puerro combina muy bien con la patata en una sopa.

But the original sentence is perfectly natural.

Literally it is very well, but in this kind of sentence it means something like:

• really well
• very nicely
• especially well

So queda muy bien con is a very natural way to say that two ingredients are an especially good match.

Compare:

• queda bien con = goes well with
• queda muy bien con = goes very well with / works really well with

Usually, in this sentence, con la patata sounds more natural in standard Spanish.

Because the sentence is talking about ingredients in a general way, Spanish normally keeps the article:

• El puerro queda muy bien con la patata.

Dropping the article is less natural here. In recipe-style language, article use can sometimes vary, but in a normal sentence like this, la patata is the expected form.

No. It is used much more broadly.

Very common meanings include:

• to suit someone
  
  • Ese vestido te queda bien.
• to look good with something
  
  • El azul queda bien con el blanco.
• to go well with in food or design
  
  • El puerro queda bien con la patata.

So this sentence uses a very common Spanish pattern that also appears with clothes, colours, furniture, decoration, and other combinations.