Roštilj lepo miriše.

• Roštilj = a noun
• lepo = an adverb
• miriše = a verb

So the structure is basically:

noun + adverb + verb

Because lepo modifies the verb miriše. In English, we also usually use an adverb with a verb: smells nicely/pleasantly—although English normally says smells nice.

• lep = beautiful / nice as an adjective
• lepo = nicely / pleasantly as an adverb

Serbian commonly uses the adverb here: lepo miriše = smells nice / smells pleasant.

Miriše is the 3rd person singular present tense form of the verb mirisati.

So:

• mirisati = to smell / to have a scent
• miriše = smells

Since roštilj is singular, the verb is also singular.

It is in the nominative singular because it is the subject of the sentence.

So:

• roštilj = the barbecue / barbecue as the thing doing the action of smelling nice

Serbian does not have articles like a and the.

So Roštilj lepo miriše can mean:

• The barbecue smells nice
• Barbecue smells nice

Which one sounds best in English depends on context, but Serbian does not mark that difference with an article.

Yes, it is natural and easy to understand. It means that the barbecue or grilled food has a pleasant smell.

A very common alternative is:

Roštilj dobro miriše.

That also means The barbecue smells good. In everyday speech, dobro miriše may even sound a bit more common to many speakers, but lepo miriše is also perfectly normal.

Yes. Serbian word order is fairly flexible.

The neutral order here is:

Roštilj lepo miriše.

But you may also hear:

• Roštilj miriše lepo.
• Lepo miriše roštilj.

These versions are not identical in emphasis. Serbian often changes word order to shift focus, rhythm, or style. For a learner, Roštilj lepo miriše is the safest basic version.

A rough pronunciation guide:

• roštilj ≈ ROSH-teely
• lepo ≈ LEH-po
• miriše ≈ MEE-ree-sheh

Useful sound notes:

• š sounds like sh in ship
• lj is a soft sound, roughly like ly in million for English speakers
• č, ć, š, ž, đ are all important Serbian consonants, so it is good to get used to them early

Not necessarily in a poetic sense. Lepo is often broader than English beautifully. In everyday Serbian, it can mean:

• nicely
• pleasantly
• well in some contexts

So lepo miriše is best understood as smells nice or smells pleasant, not literally smells beautifully.

Yes, potentially. Roštilj can refer to:

• the grill/barbecue setup
• the barbecue meal
• grilled meat/food

Context usually makes it clear. If people are cooking and someone says Roštilj lepo miriše, they are probably talking about the food or the barbecue in general, not just the metal grill.

A very common pattern is:

miriše na + accusative

For example:

• Roštilj miriše na dim. = The barbecue smells like smoke.
• Roštilj miriše na meso. = The barbecue smells like meat.

So miriše is often used either by itself, as in your sentence, or with na to say what kind of smell something has.