Preheat oven to 350 degrees Fahrenheit
In a large skillet heat the olive oil on medium heat
Saute the onions for 2-3 or until softened
Add the garlic and continue sauteing
Add the oregano, basil, zucchini, squash and carrots
Stir frequently and add salt. Cook for 5 minutes or until the veggies start to soften
Add the mushrooms and cook for 2 more minutes
Add the tomato sauce and reduce the heat to simmer
Simmer for 5 more minutes. Check for seasoning
Meanwhile, empty the ricotta in a bowl and season with salt and pepper
Place 3 noodles in a 9x13" rectangular baking pan in a way they cover the bottom of the pan
Add 1/3 of the ricotta sauce on top of the noodles
Spread 1/2 of the veggie filling on top
Cover with 3 more lasagna noodles
Spread 1/3 of the ricotta sauce on top
Cover with the rest of the veggie filling
Finally cover the top with 3 more lasagna noodles
Spread the remaining ricotta
Sprinkle mozzarella cheese on top
Cover the pan with aluminum foil
Bake for 40-45 minutes or until bubbly
Remove foil and broil for 2-3 more minutes or until the top has browned
Remove from oven and wait 10-15 minutes before cutting
Enjoy!