This is my healthier take on a comforting classic. I call it my "ugly" lasagna because when you scoop it out of the slow cooker into a bowl, it's not all nicely layered. It's just a big pile of comfort food!
Technique tip: This recipe is pretty adaptable based on how many you want to feed and how big your slow cooker is. If you use all the noodles, all the sauce and a ton of veggies, this could serve more than the 4 to 6 people mentioned above. If you use half the noodles, half the sauce, and not so many veggies, you could serve just a few. In general, estimate 2 to 3 ounces dry pasta and 3/4 to 1 cup sauce per person.
Swap option: Add any other veggies you might want to sprinkle in. You can sauté any of these along with the onions and peppers, or leave them raw: sliced mushrooms, chopped-up broccoli, more diced bell peppers, quartered cherry tomatoes, half-moon slices of zucchini and/ or yellow squash, sliced okra, shredded carrots, shredded cabbage, etc.
In a large skillet, heat the olive oil over medium heat. Add the onion and bell pepper (and any other veggies you want to add) and cook, stirring, until the onion is just turning golden brown and the bell pepper is soft. Set aside.2.
Spray a slow cooker with a light coating of cooking spray, then cover the bottom with a thin layer of the sauce (just enough to coat the bottom).3.
Break the noodles and fit them over the sauce to mostly cover the bottom in one layer. Spread a thin layer of spinach over the noodles and sprinkle with the onion-bell pepper mixture and whatever other veggies you have prepared. Top with a thin layer of sauce and then a thin layer of cheese and a few shakes of Italian seasoning.4.
Repeat layers of noodles, spinach, extra veggies, sauce, cheese and seasoning, until you reach the top of the slow cooker or run out of ingredients. End with a final layer of sauce and seasoning.5.
Cover and cook the lasagna on high for 2-3 hours or on low for 3-4 hours. Check it periodically to make sure the edges aren't burning. It should be done within a couple of hours, but you can test to make sure the noodles are tender. When you're ready to serve it, scoop it out into bowls.