Cook lasagna noodles according to package directions. Drain and rinse noodles. Lay each noodle out flat on non stick surface (you don't want noodles to stick together).

Cut sausage links in half lengthwise and then into bite size pieces. Heat olive oil in a large skillet over medium-high heat. Cook sausage until light brown. Remove sausage from skillet and set aside.

Add tomatoes to the skillet , cook until slightly soft. (approx. 2-3 min) Turn off heat, add spinach, set aside.

Warm marinara sauce in a small pan (or the microwave). set aside

Cut cooked lasagna noodles in half. Assemble lasagna by layering one of the ½ noodles with a thin layer of marinara sauce. Top with tomato and spinach mixture. Add sausage pieces(about ½ sausage) and a sprinkling of feta cheese. Repeat. Add the final ½ noodle, a layer of marinara sauce, followed by additional spinach and tomato mixture. ( A total of 3 noodles (½ noodles) will used for each piece of lasagna) . Sprinkle with feta and serve.