1/2 onion, diced
4 cups spinach (I can't believe I forgot!!) chopped
Bring 3 quarts of water to a boil in a large pot. Then add noodles, cook for 12 minutes then move to a cookie sheet for cooling (make sure to separate)
In another pan, or pot saute garlic, onion, celery and carrot in a bit of oil until tender 8-10 minutes. Then stir in wine and thyme and let reduce for a few minutes. Stir in cayenne and tomato puree and allow to heat for 10-15 minutes. Then add the lentils to this mixture heating for another 10 minutes or so. Stir in chopped spinach, which will wilt.
Preheat oven to 350*F
Layer a 9x13 baking dish with a bit of sauce. Then begin to line up shells, filling with a bit of the sauce as you go. Then top with remaining sauce, and cheese (if using) and bake uncovered for about 30 minutes.