Portal - Recipe, Ingredients and Nutritional Elements

Good morning guys, 
I am relatively new in filemaker however it is amazing how quickly you can develop an application that saves us a lot of time.

However, it is a week that I got stuck in development.

I am creating a database for the management of some recipes, for which I need to select all of the ingredients (in a portal) and make sure to display on another portal the list of the nutritional elements.

For this I created three tables "Recipes", "ingredients", "nutritional elements", plus 2 join tables "Recipes & Ingredients" and "Ingredients & Nutritional elements".

For example, the recipe "Spaghetti Bolognese" is composed of "pasta 50%" and "tomato 50%".

The problem is this: in the portal I must display the nutritional element name and its concentration (10% crude protein), whose concentration is the sum of the protein made from pasta, and the protein made from tomatoes (so it is a field calculated).

I ask you for advice on how to proceed.