In a large pot of salted water, cook the past shells according to the directions. Drain and toss the 1 tablespoon of olive oil until all the shells are coated. Set aside.
In a large bowl, combine the pre-cooked shrimp, ricotta, boursin cheese, steamed kale or spinach, basil, red pepper flakes, garlic powder, onion powder and ¼ cup of the grated parmesan cheese. Season with salt and pepper. Set aside.
In 11x7 baking dish, pour ½ of the jar alfredo sauce or just enough to cover the bottom.
Then carefully, fill each shell with the a tablespoon or two of the ricotta filling. Arrange the stuffed shells on top of the sauce. Repeat until all the ingredients are used.
Pour the remaining sauce over the filled shells and sprinkle the remaining parmesan cheese on top.
Preheat oven to 350℉.
Cover the baking dish with foil and bake for 15 minutes.
Uncover and broil for 3-5 minutes, rotating the baking dish halfway through. Serve immediately!