How can I accelerate progress in boys Writing?

I did a focus lesson with a small group of 3 boys today. I know that 1 in particular is crazy about dinosaurs and this encourages the other boys to play and talk about dinosaurs with him.
Today I showed them a picture from a book I have read to them a few times with dinosaur fighting a boy with a sword.
During their think pair share time I heard some amazing language for example- shiny sword, sharp and pointy teeth. The sentence that I was most blown away by was " This human tastes like sausage." (To which we added roared the dinosaur).
I have been putting a big focus on feeding and building on vocabulary and I can see this developing very quickly.
After they finished writing with me I sent them outside to write some basic sight words and the young boys who loves dinosaurs came running in to show me this piece of writing.

"I like dinosaurs"

Therefore I am going to accelerate boys Writing progress in my class by using exciting and engaging topics and really building on oral language before they begin writing.