Learn Hardcore Japanese: yakisoba no morituke ga kirei da to, kodomotati ha sugu tabetagarimasu. - If the yakisoba is plated nicely, the children want to eat it right away.

焼やきそば　の　盛もり付つけ　が　きれい　だ　と、　子供こどもたち　は　すぐ　食たべたがります。yakisoba no moritsuke ga kirei da to, kodomotachi wa sugu tabetagarimasu.

If the yakisoba is plated nicely, the children want to eat it right away.

Breakdown of yakisoba no moritsuke ga kirei da to, kodomotachi wa sugu tabetagarimasu.

Questions & Answers about yakisoba no moritsuke ga kirei da to, kodomotachi wa sugu tabetagarimasu.

What does 焼きそばの盛り付け mean?

It means the plating/presentation of the yakisoba.

焼きそば = yakisoba
盛り付け = arrangement on the plate, plating, presentation

So this is not talking about the taste yet. It is talking about how the yakisoba looks when served.

What is の doing in 焼きそばの盛り付け?

Here, の links two nouns.

So:

焼きそば = yakisoba
盛り付け = plating/presentation
焼きそばの盛り付け = the plating of yakisoba / yakisoba presentation

This is a very common noun-linking use of の. You can think of it as something like of or as making one noun describe another.

Why is が used after 盛り付け?

が marks 盛り付け as the subject of きれいだ.

In other words, the sentence is saying:

焼きそばの盛り付けがきれいだ = the yakisoba presentation is pretty

Here, what is pretty?
The answer is 盛り付け, so it gets が.

Using は instead would change the nuance and make it more of a topic/contrast. が is the most natural choice here for identifying what has the quality きれい.

Why is it きれいだ and not just きれい?