Mince 6 cloves of garlic and 1 onion.
Dice 1 bell pepper and cut 1 8 oz. package button mushrooms into small slices.
Roughly chop 1 cup fresh spinach.
Heat a large cast iron skillet to medium. Add 1 Tbsp. olive oil. Once the oil is heated, add the garlic and onions and saute for 2-3 minutes, stirring often.
Add the sliced mushrooms along with a pinch of salt and pepper. Saute the mushrooms for 4-5 minutes, stirring often. The mushrooms will cook down quite a bit.
Add the diced pepper to the mushrooms and saute for an additional 3-4 minutes, stirring often.
Add 1 24 oz. jar of marinara sauce and 1 ½ cups of vegetable broth to the mushrooms and peppers. Stir to combine.
Break 8-10 dry gluten free lasagna noodles (or regular lasagna noodles if not gluten free) into small pieces and add to the pan. Stir the noodles into the sauce. The noodles cook in the sauce so it is important that all the noodles are submerged in the liquid.
Bring the sauce to a low boil and then reduce to a simmer. The sauce should bubble lightly as it cooks. The heat should be hot enough to cook the noodles but not hot enough to cause the sauce to splatter - Medium/low should work fine.
Cook the noodles on a low boil for 30 minutes. Stir the noodles every 5 minutes or so (more important toward the 30 minute mark) to prevent them from sticking to the pan. Add an additional ½ cup of vegetable stock as the noodles cook.
Once the noodles are cooked and have absorbed most of the sauce, add the cup of chopped spinach and stir into the lasagna.
Turn the oven broiler on.
Spoon ½-3/4 cup of ricotta cheese on top of the lasagna in chunks (do not stir ricotta into lasagna) and sprinkle ½-3/4 cup shredded mozzarella on top of ricotta.
Place the pan in the oven directly under the broiler for 2 minutes or until the cheese melts. Remove pan from oven.
To serve: Sprinkle ¼ cup Parmesan cheese, 2 tsp. red chili flakes, and ½ cup chopped fresh basil on top of lasagna (optional).