Preheat the oven to 350°F.
Bring a large pot of water to a boil. Once boiling, add the lasagna noodles and cook according to package directions, drain, and set aside.
Meanwhile, heat the oil in a large-sided skillet over medium heat. When hot, add the onions, garlic, salt, and pepper and cook, stirring, until the onions are translucent, 3 to 5 minutes.
Increase the heat to medium-high and add the turkey, oregano, and pepper flakes (if using). Cook, breaking up the turkey with the edge of a wooden spoon until it is no longer pink and cooked through, about 6 minutes. Add in the crushed tomatoes, wine, water, basil, and thyme and stir to combine. Bring to a simmer and cook, stirring occasionally, until the sauce has reduced just slightly. Remove from the heat and set aside.
Meanwhile, in a medium bowl, with a fork, stir the ricotta, egg, parsley, lemon zest, parmesan cheese, salt, and pepper until well combined. Set aside.
To assemble the lasagna, pour 1 cup of the turkey/tomato mixture into the bottom of a 2.5-quart oval baking dish and spread to evenly coat the bottom. Top with 3 of the lasagna noodles. Next, carefully spread 1/2 of the ricotta mixture over the tops of the noodles to coat evenly. Then, sprinkle with 1/3 of the mozzarella. Top with 1 cup of the turkey/tomato mixture.
Repeat once again by layering 3 more of the lasagna noodles, spreading the remaining ricotta mixture evenly over the noodles, sprinkling 1/3 of the mozzarella, and topping with 1 more cup of the turkey/tomato mixture.
For the last layer, top with the 3 remaining lasagna noodles. Spread the remaining turkey/tomato mixture over the top. Use a rubber spatula to tuck any of the noodles into the sides so they are no longer poking out. Sprinkle the top with the remaining mozzarella cheese.
Cover the baking dish with foil and transfer to the oven and bake, covered, for 45 minutes. Uncover and continue baking until the sauce is bubbling, about 15 more minutes. Let rest for 10 minutes before slicing and serving.