El pollo con romero y tomillo queda muy bien en el horno.

Quedar bien is a very common Spanish expression used to say that something turns out well, works well, or comes out nicely in a certain context.

In cooking, quedar bien often means that an ingredient or dish is especially suitable or turns out delicious/prepared well with a certain method.

So here:

El pollo con romero y tomillo queda muy bien en el horno
means something like
Chicken with rosemary and thyme comes out really well in the oven
or
Chicken with rosemary and thyme works very well when oven-cooked.

Compare:

• es muy bueno = it is very good, in a more general sense
• está muy bueno = it tastes very good / it is very tasty
• queda muy bien = it turns out very well / it works really well

So queda muy bien is especially natural here because the speaker is talking about the result of cooking it in the oven.

Here, quedar does not mean to stay or to remain, even though that is one of its common meanings.

In this sentence, quedar means something closer to:

• to turn out
• to come out
• to work out
• to suit the preparation

This verb is very flexible in Spanish. Some common uses are:

• La sopa quedó muy rica. = The soup turned out very tasty.
• Ese color te queda bien. = That color suits you.
• Nos queda poco tiempo. = We have little time left.

So in your sentence, queda muy bien is the resultative use: the chicken comes out nicely when cooked this way.

Because the subject is el pollo, which is singular.

The phrase con romero y tomillo is just extra information describing the chicken. It does not change the number of the subject.

Breakdown:

• El pollo = the chicken → singular subject
• con romero y tomillo = with rosemary and thyme → descriptive phrase
• queda = singular verb form

So Spanish agrees the verb with el pollo, not with romero y tomillo.

If the subject were plural, then you would use quedan:

• Los pollos con romero y tomillo quedan muy bien en el horno.

Spanish often uses the definite article with general nouns, especially when talking about food items in a general way:

• El pollo = chicken / the chicken

Here, el pollo can refer to chicken as a dish or meat in a fairly general sense.

With ingredients like herbs, Spanish often leaves out the article when they are used after con:

• con romero y tomillo = with rosemary and thyme

That sounds natural and idiomatic. You could sometimes hear articles in other contexts, but in recipes or food descriptions, omitting them is very common.

So this pattern is normal:

• El cordero con ajo queda muy bien.
• La patata con pimentón está muy rica.

Literally, en el horno means in the oven, but in natural English translation it often corresponds to:

• in the oven
• when cooked in the oven
• oven-baked
• roasted, depending on context

In Spanish, en el horno is the normal way to say that something is cooked using the oven.

Examples:

• Se hace en el horno. = It is made in the oven.
• El pescado queda muy bien en el horno. = Fish turns out very well in the oven.

So yes, it literally says in the oven, but functionally it means when oven-cooked.

This is the most neutral and natural word order in Spanish:

• subject: El pollo con romero y tomillo
• verb: queda
• adverb: muy bien
• place/method phrase: en el horno

Spanish is more flexible than English with word order, but this order sounds very standard.

Other orders are possible for emphasis, for example:

• En el horno, el pollo con romero y tomillo queda muy bien.
• El pollo queda muy bien en el horno con romero y tomillo.

But those versions can shift the focus slightly, and the original is the clearest and most natural for a general statement.

It describes the result of the chicken when prepared that way.

In queda muy bien, the phrase muy bien modifies queda, so it tells you how it turns out.

So the meaning is not exactly:

• the chicken is very good

but rather:

• the chicken turns out really well
• the combination works really well
• it comes out very nicely

This kind of adverbial phrase is very common with quedar:

• queda bien
• queda muy bien
• queda fatal
• queda perfecto

Yes, but they mean slightly different things.

• sabe muy bien = it tastes very good
• está muy bueno = it is very tasty
• queda muy bien = it turns out very well / works really well

So:

• El pollo con romero y tomillo sabe muy bien.
  focuses on taste.

• El pollo con romero y tomillo está muy bueno.
  also focuses on the final taste/quality of the dish.

• El pollo con romero y tomillo queda muy bien en el horno.
  focuses more on the success of this preparation method.

This makes queda muy bien en el horno especially appropriate if you are giving cooking advice or describing what method suits the dish.

Yes. Like many food words in Spanish, pollo can refer to:

• the animal: a chicken
• the meat: chicken
• a chicken dish: the chicken

Context tells you which one is meant.

In your sentence, it clearly refers to chicken as food, not the live animal, because of:

• con romero y tomillo
• en el horno

So this is a culinary use.

Here con means with, and in a cooking context it usually implies that the chicken is prepared/seasoned/cooked with rosemary and thyme.

So:

• pollo con romero y tomillo
  means
• chicken with rosemary and thyme
• chicken seasoned with rosemary and thyme
• chicken cooked with rosemary and thyme

Spanish often uses con very naturally for ingredients, seasoning, and accompaniment:

• pasta con tomate
• cordero con ajo
• patatas con romero

It does not need a more complicated structure.

Yes, it sounds natural in Spain.

It has a very standard, idiomatic feel, especially in spoken Spanish or food writing. A Spanish speaker might say it when recommending how to cook chicken or describing a good flavour combination.

It sounds like the kind of sentence you might hear in:

• a cooking conversation
• a recipe blog
• a TV cooking show
• casual advice about food

It is neither too formal nor too slangy.

No—that would be a misleading translation.

Even though quedar can sometimes mean to stay/remain, that is not what it means here. In this sentence, the natural meaning is about how the dish turns out.

A better translation would be:

• Chicken with rosemary and thyme turns out really well in the oven.
• Chicken with rosemary and thyme is excellent when cooked in the oven.
• Chicken with rosemary and thyme works very well in the oven.

So this is a good example of why Spanish verbs should be translated by meaning in context, not by one fixed English equivalent.

Yes, but it would change the meaning slightly.

• en el horno = in the oven / when cooked in the oven
• al horno = baked / oven-cooked / prepared in the oven

For example:

• El pollo con romero y tomillo queda muy bien en el horno.
  = Chicken with rosemary and thyme turns out very well in the oven.

• El pollo al horno con romero y tomillo queda muy bien.
  = Oven-baked chicken with rosemary and thyme turns out very well.

So al horno often acts more like a description of the dish itself, while en el horno points more directly to the cooking method or place of cooking.