Place the cashews in a bowl and cover them with filtered water. Soak for 4 or more hours.
Drain the cashews and place them in a food processor. Add the vinegar, non-dairy milk, and salt. Process until mostly smooth with a few chunky bits.
Pesto
Place the basil, walnuts, garlic, miso, nutritional yeast, pepper, salt, and lemon juice in a food processor. With the motor running, drizzle in the olive oil until you have a coarse but grainy and consistent paste. Scrape down the sides of the processor if needed.
Adjust the salt and pepper seasoning to taste. Check the seasoning and add more ground pepper and salt if needed.
Lasagna
Bring a large pot of water to a boil over medium-high heat. Season the water generously with salt. Add the lasagna noodles and cook until just al dente. Drain the noodles in a colander and give a quick rinse in cool water to stop the cooking.
Slice the zucchini into long thin planks. In a skillet on medium heat, add the oil and cook the zucchini until just tender, approximately 2 minutes per side. Drain on paper towels.
Chop the kale into bite-sized pieces. Mince the parsley. In a mixing bowl, combine the cashew ricotta with the kale and parsley.
Preheat your oven to 375°F.
Take a square or rectangular glass baking dish and lightly oil the bottom and sides. Assemble the lasagna: one layer of noodles, 1/4 quarter of the pesto, 1/4 of the ricotta, and 1/3 of the zucchini. Repeat until you have 4 layers of pasta. The top layer of noodles will get 1/4 of the pesto and 1/4 of the ricotta. Tope the entire lasagna with the diced tomatoes.
Cover the lasagna with aluminum foil. Place it in the oven and bake for 35 minutes until bubbling.
Allow the lasagna to cool slightly so it will set up before digging into it. Enjoy while still warm.