Yes, you can provide up to 10 options per meal type in the meal planner.
To do that, open the meal plan you would like to edit and click on the 3 dots button on the meal to see the options available. After that, you can add another recipe or food that will add it into the same meal type. Your client will see these options in the mobile app as well and be able to scroll through the options.
You can also do this for meal plan templates following the same process.