Broccoli smager bedre, når min mor steger den hurtigt med smør og lidt salt.

In Danish, food items and substances often appear without an article when you mean them in a general sense.

So Broccoli smager bedre ... means Broccoli tastes better ... in a general way.

If you wanted to talk about a specific broccoli, you could use an article, for example:

• Broccolien smager godt. = The broccoli tastes good.
• En broccoli ligger på bordet. = A broccoli is lying on the table.

Here, Broccoli is being talked about as a type of food, so no article is needed.

Smager is the present tense of at smage, which means to taste.

So:

• broccoli smager bedre = broccoli tastes better

This verb is used for flavor, not for visually trying food with your mouth. Compare:

• Det smager godt. = It tastes good.
• Jeg smager suppen. = I taste the soup.

In your sentence, smager describes how broccoli tastes.

Bedre is the comparative form of god/godt and means better.

This is an irregular comparison:

• god = good
• bedre = better
• bedst = best

So:

• Broccoli smager godt. = Broccoli tastes good.
• Broccoli smager bedre. = Broccoli tastes better.

Danish, like English, has some irregular comparatives, and this is one of the most common ones.

Just like in English, Danish can leave the comparison implicit if the context is understood.

So Broccoli smager bedre can mean:

• Broccoli tastes better
• Broccoli tastes better this way
• Broccoli tastes better than usual
• Broccoli tastes better than when prepared differently

You do not need to add end ... (than ...) unless you want to make the comparison explicit.

For example:

• Broccoli smager bedre end blomkål. = Broccoli tastes better than cauliflower.

Når usually means when in the sense of something that happens regularly, typically, or whenever.

In this sentence:

• når min mor steger den hurtigt ... = when my mother fries/pan-fries it quickly ...

This suggests a repeated or general situation: broccoli tastes better whenever or when my mother cooks it this way.

A very important contrast is:

• når = when / whenever, usually for repeated events or future situations
• da = when, for a specific event in the past

Examples:

• Når min mor laver mad, smager det godt. = When my mother cooks, it tastes good.
• Da min mor lavede mad i går, smagte det godt. = When my mother cooked yesterday, it tasted good.

Steger is the present tense of at stege, which means to fry, to roast, or more generally to cook with dry heat, depending on context.

Here, because the broccoli is cooked med smør (with butter) and hurtigt (quickly), the most natural English idea is:

• fries
• pan-fries
• sautés

So min mor steger den hurtigt med smør means something like:

• my mother quickly fries it in butter
• my mother quickly sautés it with butter

Because broccoli is a noun with grammatical gender, and in Danish it is a common gender noun, so the pronoun is den.

Danish uses:

• den for common gender nouns
• det for neuter nouns

So even though broccoli is not a person, Danish still refers back to the noun with a gendered pronoun based on grammar, not natural sex.

For example:

• broccoli → den
• et æble → det

In your sentence:

• min mor steger den = my mother fries it

Here hurtigt is being used as an adverb, meaning quickly.

The adjective is:

• hurtig = quick

But when it describes how an action is done, Danish often uses the -t form:

• hurtigt = quickly

So:

• en hurtig bil = a fast car
• hun løber hurtigt = she runs quickly

In your sentence, it describes how the mother fries the broccoli:

• steger den hurtigt = fries it quickly

Lidt means a little or a bit.

So:

• lidt salt = a little salt

Here lidt is a quantity word, not an adjective meaning small.

Compare:

• lidt salt = a little salt
• et lille glas = a small glass

So med smør og lidt salt means:

• with butter and a little salt

Because når introduces a subordinate clause, and subordinate clauses in Danish usually keep the subject before the verb in normal order.

So:

• når min mor steger den hurtigt
  = when my mother fries it quickly

Inside that clause:

• min mor = subject
• steger = verb

That is normal subordinate-clause word order.

The full sentence begins with the main clause:

• Broccoli smager bedre

and then adds the subordinate clause:

• når min mor steger den hurtigt med smør og lidt salt

If you put the når-clause first, then the main clause would show inversion:

• Når min mor steger den hurtigt med smør og lidt salt, smager broccoli bedre.

Notice how smager comes before broccoli in the main clause after the fronted clause.

Yes, min mor is completely normal and natural. It simply means my mother / my mom, depending on context and tone.

Danish also has:

• min mor = my mother / my mom
• min mor laver mad = my mother is cooking / my mom cooks

It is neither unusually formal nor unusually childish. It is a very common everyday expression.

Yes, the comma before når is standard because når min mor steger den hurtigt med smør og lidt salt is a subordinate clause.

So the sentence is divided like this:

• Broccoli smager bedre,
• når min mor steger den hurtigt med smør og lidt salt.

In modern Danish writing, commas are normally used to separate a main clause from a subordinate clause like this.

A learner will often find these words tricky:

• smør — the vowel is unusual for English speakers. It is roughly like a rounded vowel, somewhat similar to the vowel in French peur or German hören, depending on accent.
• steger — the first syllable sounds roughly like stay- but not exactly English stay; the g is soft here.
• bedre — often sounds closer to BEL-thruh / BED-ruh depending on accent, not a strongly pronounced final r like in English.
• hurtigt — the ending can be reduced in natural speech.

A good general tip: for words like smør, it is much better to listen and imitate native audio than to rely on English-style spelling approximations.

Yes, but it changes the meaning slightly.

• Broccoli smager bedre ... = broccoli in general tastes better ...
• Broccolien smager bedre ... = the broccoli tastes better ...

So if you are speaking generally about broccoli as a food, the sentence you were given is the most natural.

If you are talking about a specific portion on the table, then broccolien would make sense.

The structure is:

• Broccoli = subject/topic
• smager = verb
• bedre = complement/comparative
• når min mor steger den hurtigt med smør og lidt salt = subordinate clause explaining when/under what circumstances

So a simple breakdown is:

• Broccoli smager bedre
  = Broccoli tastes better
• når min mor steger den hurtigt med smør og lidt salt
  = when my mother quickly fries it with butter and a little salt

This is a very natural Danish sentence with a main clause followed by a når-clause.