Esta noche voy a hacer merluza a la plancha para la cena.

Ir a + infinitive is a very common way to talk about a planned or expected future action, especially in everyday speech.

So voy a hacer merluza means something like I’m going to make hake.

You could also say Esta noche haré merluza a la plancha, and that is grammatically correct. But voy a hacer often sounds a bit more natural and conversational when talking about plans.

A rough contrast:

• Voy a hacer... = I’m going to make...
• Haré... = I will make...

In many situations, Spanish speakers use ir a + infinitive where English speakers might also naturally say I’m going to....

Yes. In Spanish, hacer is often used for preparing food, especially in everyday speech.

So hacer merluza means to make / cook / prepare hake.

This is very common with dishes and meals:

• hacer la cena = to make dinner
• hacer una tortilla = to make an omelette / Spanish omelette
• hacer pasta = to make pasta

Other possible verbs are:

• cocinar = to cook
• preparar = to prepare

So you could also hear:

• Voy a cocinar merluza
• Voy a preparar merluza

But hacer is extremely natural.

Because here merluza is being treated like a food item or ingredient in a general sense, not as a specific individual fish.

Spanish often omits the article with foods after verbs like comer, hacer, preparar, etc., when speaking generally:

• Voy a hacer merluza = I’m going to make hake
• Comemos pollo = We eat chicken
• Quiero preparar arroz = I want to prepare rice

If you add the article, it can sound more specific:

• Voy a hacer la merluza = I’m going to make the hake

That would usually suggest a particular hake already mentioned or understood.

A la plancha is a very common cooking expression meaning grilled on a flat hot surface, griddle-cooked, or sometimes simply pan-grilled.

A plancha is a metal cooking surface. So:

• merluza a la plancha = grilled hake / hake cooked on a hot plate

You will see this pattern with many foods:

• pollo a la plancha = grilled chicken
• calamares a la plancha = grilled squid
• verduras a la plancha = grilled vegetables

It is a fixed culinary expression, so it is best learned as a chunk: a la plancha.

Because a la + noun is a common Spanish structure for describing a style or method of preparation.

Examples:

• a la plancha = grilled / cooked on a hot plate
• a la parrilla = grilled on a grill
• a la brasa = cooked over embers
• a la catalana = Catalan-style

So here a la plancha does not literally function like a normal location phrase. It is an established way of saying in the style/method of the griddle.

Esta noche is a time expression meaning tonight, and putting it at the beginning is very natural because it sets the time frame immediately.

Spanish word order is fairly flexible, so these are all possible:

• Esta noche voy a hacer merluza a la plancha para la cena.
• Voy a hacer merluza a la plancha esta noche para la cena.
• Voy a hacer esta noche merluza a la plancha para la cena.
  This last one is less natural in many contexts.

Starting with Esta noche is very common because it sounds smooth and clear.

In Spain Spanish:

• esta tarde = this afternoon / this evening
• esta noche = tonight / this night

A learner may expect noche to mean only night, but in Spanish esta noche is exactly how you normally say tonight.

So if the meal is dinner, esta noche makes perfect sense.

Because para expresses purpose or intended use here.

• para la cena = for dinner

It answers the idea What is it for?
Answer: for dinner.

Using por would not work naturally here. Por has other uses, such as cause, exchange, movement through, and so on.

Compare:

• Lo hice para la cena. = I made it for dinner.
• Lo hice por ti. = I did it for you / because of you.

So para la cena is the correct choice.

Yes, you could say para cenar, and it would sound very natural.

Compare:

• para la cena = for dinner
• para cenar = to have for dinner / for dinner

Both are good, but they are structured differently:

• la cena is a noun: dinner
• cenar is a verb: to have dinner / to eat dinner

So these are both natural:

• Esta noche voy a hacer merluza a la plancha para la cena.
• Esta noche voy a hacer merluza a la plancha para cenar.

The first focuses on the meal; the second focuses more on the action of eating dinner.

Not in this sentence. Para cena is not natural standard Spanish here.

You normally need either:

• para la cena or
• para cenar

So if you want a noun, use la cena. If you want a verb, use cenar.

Yes. The sentence pattern is very reusable:

• Esta noche voy a hacer salmón a la plancha para la cena.
• Esta noche voy a hacer pollo a la plancha para la cena.
• Esta noche voy a hacer verduras a la plancha para la cena.

So the useful pattern is:

Esta noche voy a hacer + food + a la plancha + para la cena.

This makes the sentence a great model for building similar ones.

Merluza is the normal word for hake, and it is very common in Spain, where hake is a very typical food.

The word itself is not only used in Spain, but the sentence feels especially natural in a Spain context because:

• hake is very common there
• a la plancha is a very typical way of describing food
• the whole sentence sounds like everyday Peninsular Spanish

So a learner of Spanish from Spain should definitely recognize and learn this kind of phrasing.

Yes, but the meaning focus changes.

• Voy a hacer merluza a la plancha = I’m going to make/cook grilled hake
• Voy a cenar merluza a la plancha = I’m going to eat grilled hake for dinner

So:

• hacer focuses on preparing the food
• cenar focuses on eating it

If the speaker is the one cooking, hacer is exactly right. If the speaker just means what they will eat, cenar could be better.