Laravel Model Count By Relationship

I have an eCommerce site with a Product model and a ProductCategory model. I currently show products on the page from the Product model but would like to be able to get list of all the categories with products in the current model and how many products are in each category. I can get the overall count but can't figure out how to get the list of categories being shown and how many results per category have been returned.

via Chebli Mohamed