Pre-heat oven to 375 degrees and grease a 9x13 casserole dish.
In a large bowl, add the ricotta cheese and cream cheese and mix until smooth. Toss in the sun-dried tomatoes, spinach, cajun seasoning, chicken and cheese and fold until combined.
Boil noodles to al dente according to the package instructions.While noodles are cooking, make a quick alfredo sauce by combining butter and garlic over medium-low in a saucepan. Saute until garlic is fragrant, then add heavy cream.
Whisk in cajun seasoning and parmesan and simmer for 5-6 minutes or until it thickens slightly.
Add a few spoonfuls of sauce into the bottom of a greased 9x13 casserole pan. To assemble, scoop 2/3 cup filling onto the end of each cooked lasagna sheet. Roll them up taut and place them seam-side down, side by side into the baking dish. Repeat with remaining lasagna rolls until pan is filled (about 10-12 rolls).
Pour the warm alfredo sauce evenly over the rolls, spooning any sauce that falls into the crevices back on top of the lasagna rolls. Spread 1.5 cups of shredded cheese on top the rolls and bake uncovered for 35 minutes, or until edges are crisp and bubbling and top is turning golden brown.