I feel like sometimes it's important not to over-complicate copy. I think that if I saw these posts, they would stay with me.

 Post 1 is all about peri peri, because it is a USP for the burger. 

The second post establishes brand recall for Leon Grill, directs the viewer to the food joint and also mentions the name of the product in the copy unlike the other two posts, which focus on one particular component of the product. 

Post 3 again focuses on the components of the burger and creates a visual representation of the taste/feel which makes the product appealing.

Hashtags remain common for all three posts, but in real life (as a social media strategist) I would mix and match to see which combination works well.