Para o almoço, eu vou assar a carne com cenoura e alho.

Yes. Para o almoço literally means for lunch.

In this sentence, it means something like:

• for lunch
• as lunch
• for the lunchtime meal

A very natural English equivalent is For lunch, I’m going to roast the meat with carrot and garlic.

A learner might also notice that Portuguese often uses an article here:

• para o almoço = for lunch
• literally for the lunch

That sounds strange in English, but it is normal in Portuguese.

You may also hear the contraction:

• pro almoço = para o almoço

That is very common in spoken Brazilian Portuguese.

Sometimes, but the meaning changes.

• Para o almoço focuses on purpose: this is what will be prepared for lunch.
• No almoço means at lunch or during lunch.

So:

• Para o almoço, eu vou assar a carne... = For lunch, I’m going to roast the meat...
• No almoço, eu vou comer carne... = At lunch, I’m going to eat meat...

In your sentence, para o almoço is the better choice because the speaker is talking about what they will make for that meal.

Because ir + infinitive is extremely common in Brazilian Portuguese for talking about the future.

• eu vou assar = I’m going to roast
• assarei = I will roast

Both are grammatically correct, but they feel different:

• eu vou assar sounds more natural and conversational in everyday Brazilian Portuguese
• assarei sounds more formal, more written, or sometimes more emphatic

So in normal speech, Brazilians usually prefer:

• vou fazer
• vou comprar
• vou assar

rather than:

• farei
• comprarei
• assarei

Yes. That is very common.

Portuguese often drops subject pronouns when the verb already makes the subject clear.

• (Eu) vou assar a carne.

Both versions are correct.

Why include eu at all?

• for emphasis
• for clarity
• for contrast

For example:

• Eu vou assar a carne, e ela vai fazer o arroz.
  I am going to roast the meat, and she is going to make the rice.

So in isolation, vou assar a carne is perfectly natural.

Portuguese uses definite articles more often than English.

So a carne literally means the meat, but in many contexts English would just say meat.

In Portuguese, the article can make the noun sound more natural, especially when referring to:

• a specific item
• the main dish
• something understood from context

Here, a carne probably means the meat the speaker has in mind for that meal.

Without the article, assar carne can still exist, but it sounds more general:

• Gosto de assar carne no fim de semana.
  I like roasting meat on weekends.

In your sentence, a carne sounds more specific and natural.

It can mean either, depending on context.

In Brazilian Portuguese:

• carne often means meat in general
• but very often in daily speech it specifically suggests beef

So assar a carne could mean:

• roast the meat
• roast the beef

If someone wanted to be more specific, they could say:

• carne bovina = beef
• carne de porco = pork
• frango = chicken

In many everyday food contexts, though, carne by itself is often understood as beef.

Because when talking about ingredients in a general way, Portuguese often leaves out the articles.

So:

• com cenoura e alho = with carrot and garlic
• in natural English: with carrots and garlic or with carrot and garlic

This is similar to listing ingredients:

• arroz com feijão
• frango com batata
• macarrão com queijo

You could sometimes hear articles in other contexts, but here no articles sounds very natural.

Not necessarily.

In ingredient lists, Portuguese often uses the singular in a general or category-like way.

So com cenoura e alho can mean:

• with carrot and garlic
• with some carrot and some garlic
• with carrots and garlic

It does not mean there is only one exact carrot.

If the speaker wanted to emphasize actual countable pieces, they might say:

• com cenouras e alho
• com duas cenouras e alho

But the singular is very normal when naming ingredients in a recipe-like way.

It could mean either, depending on context.

Com is broad here. It can mean that the meat is:

• cooked together with carrot and garlic
• accompanied by carrot and garlic
• seasoned/flavored with carrot and garlic

Portuguese does not force that distinction in this sentence.

If someone wanted to be more precise, they could say:

• temperada com alho = seasoned with garlic
• assada com cenouras = roasted together with carrots
• servida com cenoura e alho = served with carrot and garlic

But as written, com cenoura e alho naturally suggests they are part of the dish.

Yes, the word order is flexible.

Your original sentence:

• Para o almoço, eu vou assar a carne com cenoura e alho.

A very natural alternative is:

• Eu vou assar a carne com cenoura e alho para o almoço.

The difference is mainly one of focus:

• Para o almoço at the beginning highlights the meal first
• para o almoço at the end sounds a little more neutral

Both are good Portuguese.

These verbs describe different cooking methods:

• assar = to roast / bake
• cozinhar = to cook / boil
• fritar = to fry
• grelhar = to grill

So:

• assar a carne = roast the meat
• cozinhar a carne = cook/boil the meat
• fritar a carne = fry the meat
• grelhar a carne = grill the meat

In your sentence, assar suggests an oven or roasting method rather than frying or boiling.

Mostly yes, but a few points may help:

• vou sounds roughly like voh with a glide, somewhat like English voh-oo said quickly
• assar has stress on the last syllable: a-SAR
• the ss makes a clear s sound
• alho is tricky for English speakers: the lh is a palatal sound, somewhat like the lli in million, but not exactly

A rough learner-friendly approximation:

• Para o almoço, eu vou assar a carne com cenoura e alho
• PA-ra u aw-MOH-su, eu voh a-SAR a KAR-ni kom se-now-ra i A-lyu

That is only approximate, but it helps with the rhythm.

In everyday Brazilian Portuguese, para is very often shortened in speech.

Common spoken forms:

• pra = para
• pro = para o
• pra o also exists in some speech, but pro is very common
• pra a often becomes pra

So your sentence might sound like:

• Pro almoço, eu vou assar a carne com cenoura e alho.

That is very natural in casual speech.

In more careful writing, para o almoço is the safer full form.