Make the Sauce Base: In a large skillet, heat oil over medium heat.
Add onion, carrot, and garlic; cook for 5 minutes until tender.
Stir in the rinsed beans, undrained tomatoes, 1/4 cup (960 ml) parsley, basil, and oregano.
Bring to a boil, then reduce heat, cover, and simmer for 15 minutes.
Cook Noodles & Preheat Oven: While the sauce simmers, cook lasagna noodles according to package directions.
Drain, rinse with cold water, and lay flat on a sheet of foil to prevent sticking.
Preheat your oven to 375°F / 190°C.
Finish the Sauce: Uncover the skillet. Lightly mash some of the beans with a fork to help thicken the sauce.
Stir in the sliced mushrooms and continue to simmer, uncovered, for 15 more minutes, stirring occasionally.
Prepare the Cheese Filling: In a medium bowl, combine the drained cottage cheese, 1/2 cup (480 ml) of the mozzarella cheese, the egg or egg product, and the Parmesan cheese.
Mix well.
Layer the Lasagna: Spread 1/2 cup (480 ml) of the bean sauce in the bottom of a 2-quart rectangular baking dish.
Arrange 2 noodles on top.
Spread with one-third of the cheese mixture.
Top with one-third of the remaining bean mixture, then half of the spinach.
Repeat the layers once more (noodles, cheese, sauce).
Finish with a final layer of 2 noodles and the last of the bean sauce.
Bake: Cover the dish with foil and bake for 40 minutes, or until hot and bubbly throughout.
Add Final Cheese & Rest: Uncover the lasagna, sprinkle with the remaining 1/2 cup (480 ml) of mozzarella cheese, and bake for 5 more minutes until the cheese is melted and golden.
Let the lasagna stand for 10 minutes before slicing and serving.
Garnish with extra fresh herbs, if desired.
