Grease a baking dish and add in the prepared mashed potatoes. Smooth it out so that it is an even layer. Next, evenly sprinkle the cubes of butter over the mashed potatoes. Then, take about ¼ of the rosemary and black garlic Boursin cheese (save the rest for later), break it up into pieces, and evenly sprinkle it over the mashed potatoes. Lastly, shake over ½ tsp of cracked black pepper. Set that aside.
In a bowl add in the remaining rosemary and black garlic boursin cheese and ¼ cup of sliced green onion. Combine that just until incorporated. Set it aside.
Season your chicken tenderloins with ½ tsp cracked black pepper and ½ tsp of salt. Now, take a spoonful of that boursin cheese green onion mixture and add it on top of the chicken tenderloin. Smooth it out to cover the chicken tenderloin evenly and repeat this process for the remaining chicken tenderloins. Then, arrange the boursin covered chicken tenderloins in an even line over the mashed potatoes.
Now, sprinkle the shredded mozzarella cheese evenly over the top. Lastly, sprinkle over ¼ cup of sliced green onions. Bake it at 400°F for 30 - 35 minutes or until browned and bubbly. Enjoy!
