Recommendations on how to make a scenario

I am designing an interactive "health" exercise where the user will able to design a balanced meal by dragging a food type (fruit, veggie, grain, dairy, protein) onto a plate. I was wondering if anyone had any ideas on how I might make it so that the user cannot click the next button until atleast 1 type of each food is dragged onto the plate.

THe part that complicated this for me is that there will be several type of "foods"  in each group that the user can drag onto the plate. For instance , in the veggies group the user has the option to drag broccoli, asparagus, or peas onto the plate. They only need to drag one of those to the plate but the plate must have one food from that group in order for the user to proceed. 

I hope I was clear on how I am trying to make this , if anyone has any idea or has done anything like this before I would appreciate any help. THanks in advance !