Preheat your oven to 350 degrees Fahrenheit.
Put tofu, oregano, basil, soy milk, onion, garlic, lemon juice and salt in the blender or food processor and pulse it for a couple of minutes or until you get a smooth paste.
Pour the paste out in a medium sized bowl before adding chopped spinach. Now stir the mixture well and set aside.
Heat oil in a large sauce pan and sauté zucchini, mushrooms, carrots and red pepper for one to two minutes.
Once the vegetables are crisp and tender, add tomato sauce and water before bringing it to boil.
After the mixture starts boiling, reduce the heat and allow the vegetables to simmer, covered for half an hour, but stir occasionally.
Remove the tofu mixture from the heat and divide it in three equal parts.
Take a lasagna pan and line its base with a thin layer of tomato sauce. The sauce should cover the bottom of the dish, but should not be flowing in the pan.
Add a layer of boiled and drained lasagna noodles, and top them with one part of the tofu mixture.
Apply another layer of lasagna noodles and pour the tofu mixture over it. Now add the final lasagna layer and pour the remaining veggie mixture over it, spreading it evenly.
Put the lasagna pan in the oven, preheated to 350 degrees, and bake it uncovered for 30 to 35 minutes.
Remove from the oven and allow it to set at room temperature for five to 10 minutes, before cutting and serving.