I steamed a bunch of finely chopped kale with a few shakes of crushed red pepper and a pinch of salt.
After about five minutes I added a cup of diced red bell peppers and white onion.
While the veggies were cooking I browned a pound of spicy Italian sausage with a drop of liquid smoke, some garlic powder, and a pinch of cajun.
I used the noodles raw. The first layer was just noodles and marinara. The next layer was the kale and marinara, and the last layer was ricotta and alfredo. The top layer is the Italian sausage, ricotta, and mozzarella. I baked it covered for about an hour at 400 and broiled the top for a couple minutes because I like it crispy.
It turned out great, the kale added a crunchy spice to the lasagna.