Heat olive oil in a large skillet over medium heat.
Add the Italian sausage and break it up as it cooks.
Add the diced onion directly to the skillet with the sausage. Continue cooking, stirring occasionally, until the sausage is fully browned and the onions are softened.
Add the canned diced tomatoes (with juices), tomato sauce, and water. If you’re using Italian seasoning, add it to season the sauce. Stir to combine.
Stir in the ricotta cheese.
Add the broken, uncooked lasagna noodles. Make sure the noodles are mostly submerged in the sauce mixture.
Add in the spinach (or other greens) and stir until it is wilted down.
Add the fresh mozzarella cheese, and cover the skillet until the cheese melts.
Sprinkle in the Maldon sea salt flakes and black pepper to taste.
Optional: Add frozen peas or zucchini and stir to combine.
Cover the skillet and simmer for 15-20 minutes, stirring occasionally to prevent the noodles from sticking.
Remove the skillet from the heat and let it sit for a few minutes to allow the flavors to settle before serving.
Once done, spoon into a bowl and sprinkle with grated Parmesan cheese.