La merluza con puré y verduras es una cena ligera y bastante completa.

Yes. La merluza means hake, a very common white fish in Spain.

A few useful notes:

• It is a countable food noun in Spanish, but here it refers to hake as a dish or serving of hake.
• In Spain, merluza is a very normal menu word, so you will see it often in restaurants and home cooking.
• It is a feminine noun, which is why it takes la.

Spanish often uses the definite article with food more than English does.

So:

• La merluza con puré y verduras... = The hake with mash and vegetables...

In English, we might leave out the in some contexts, but in Spanish it is very natural to include the article when talking about a dish or item of food in a general but specific-sounding way.

Both are possible, but they do not sound exactly the same.

In this sentence:

• con puré y verduras sounds like with mash and vegetables as part of the dish description in a general way.

If you said:

• con el puré y las verduras

it would sound more like you mean with the specific mash and the specific vegetables already known in the situation.

So omitting the articles here is very natural when listing side dishes or ingredients.

Often, yes. In many everyday food contexts in Spain, puré by itself commonly suggests puré de patatas or some kind of vegetable purée.

However, puré on its own literally just means purée / mash. The exact type may be understood from context.

So:

• puré = purée / mash
• very often in meals, learners can think of it as mash, especially if the meaning has already been provided.

Because verduras usually means vegetables as a category or side dish, and in Spanish it is very commonly used in the plural.

Compare:

• verdura = vegetable matter / greens / vegetable as a general substance word in some contexts
• verduras = vegetables

In meal descriptions, verduras is the more natural choice.

Because the subject is treated as one dish / one meal, not as separate items.

The whole phrase:

• La merluza con puré y verduras

functions as a single subject, so Spanish uses es:

• La merluza con puré y verduras es una cena ligera...

It means that this combined dish is a light, fairly complete dinner.

The noun is cena, which is feminine singular, so the adjectives must agree with it:

• ligera = feminine singular form of ligero
• completa = feminine singular form of completo

So:

• una cena ligera
• una cena bastante completa

Both adjectives describe cena, not merluza.

Here bastante means quite, fairly, or reasonably.

So:

• bastante completa = quite/fairly complete

It softens the statement a little. It suggests the dinner is not only light, but also nutritionally satisfying or well balanced.

A useful grammar point:

• When bastante works as an adverb before an adjective, it does not change form:
  • bastante completo
  • bastante completa
  • bastante completos
  • bastante completas

Because bastante is modifying the adjective completa, not the noun directly.

Structure:

• bastante completa = fairly complete

This is similar to:

• muy buena = very good
• poco útil = not very useful / little use
• bastante interesante = quite interesting

So bastante goes before the adjective it modifies.

Yes. Ligero / ligera is the normal word for light when talking about food or meals that are not heavy.

Examples:

• una comida ligera = a light meal
• una cena ligera = a light dinner

It refers to something easy to digest or not too heavy, not to physical weight.

Not necessarily. Here completa means something like well-rounded, balanced, or containing enough elements to make a proper meal.

So una cena bastante completa suggests:

• it has protein, plus sides
• it feels nutritionally sufficient
• it is a proper dinner, even if it is light

It does not necessarily mean large or filling in quantity.

Yes, it could be reversed:

• una cena bastante completa y ligera

But the original order sounds very natural because it presents the meal first as light, then adds the extra positive idea that it is also quite complete.

So the sentence flows like this:

• it is light
• and, importantly, still fairly complete

That makes good stylistic sense.

You could say resulta ser or resulta in some contexts, but es is the most straightforward and natural choice here.

• es = simply states what it is
• resulta = can suggest turns out to be, which adds a slightly different nuance

For a basic meal description, es is the best and most neutral option.

A close word-for-word version would be:

• The hake with mash and vegetables is a light and fairly complete dinner.

Spanish and English are similar here, but there are a few differences:

• Spanish uses la with merluza
• Spanish often omits articles in lists of accompaniments: con puré y verduras
• The adjective agreement is visible in Spanish: ligera, completa

So the structure is familiar to an English speaker, but the article use and adjective agreement are especially worth noticing.