Season the chicken tenders with salt and Cajun seasoning to taste. In a large skillet, heat the olive oil to medium high and cook the chicken until full cooked. Remove the chicken from the skillet and set aside.
In the same skillet, cook the chopped onion and minced garlic over medium heat until the onion becomes translucent.
slice the mushrooms and add them to the onions.
Once the mushroom has cooked for about 5 minutes, add in the flour stir until combined. Then add in the Marsala wine and heavy cream.
After the cooked chicken has cooled, dice it up into small pieces and add it to the mushrooms. Then add in the red pepper flakes, Parmesan, and salt. Stir until combined and set aside.
In a saucepan, heat butter and flour over medium heat.
Slowly add the heavy cream, milk, Marsala wine, and white pepper.
Once the sauce has heated, add in the Parmesan cheese.
Cook the lasagna pasta according to the package, making sure to add a generous amount of olive oil to the pasta water to prevent the pasta from sticking to each other.
Using tongs, remove the lasagna from the pot and lay onto sheets of paper towel.
Each piece of lasagna should be 5x7 inches. Spread about 1 heaping tablespoon of the chicken and mushroom mixture into each piece of lasagna. Then roll tightly and compress the filling from each opening using your fingers. I do this to make sure the filing is well packed inside, and won't fall out.
In 9x13 inch baking dish, spread a thin layer of the roux and place each rolled cannelloni into the dish. (You may need an additional baking dish if you want to make all of the cannelloni)
spread a generous amount of the roux on top of the cannelloni and sprinkle with the shredded Italian cheese blend.
Cover with foil and bake at 360 degrees for 50 minutes. Garnish with chopped parsley if desired.