Yes, you can create as many meal templates you need.
From the weekly planner, find the meal you want to save as a template
Click the ⋮ menu button
Click Save meal as template
The meal will now be added to your Meal Templates that you can reuse in any clients plan
You can also rename the meal to make it easier to find later
Click the ⋮ menu button
Click Rename
Alter the name and Save changes
That's it. The meal can be used in any client plan.