Heat 2 tablespoons olive oil in a large skillet over medium heat.
Add the diced onion, diced green bell pepper, and 4 teaspoons Italian seasoning; cook, stirring occasionally, until the onion is soft and translucent and the pepper is tender, about 8 minutes.
Stir in the minced garlic and cook, stirring frequently, for 1 minute.
Add the fire-roasted tomatoes (or diced tomatoes), tomato paste, 1 tablespoon honey, 1 1/2 teaspoons kosher salt, and 1/4 teaspoon black pepper.
If using whole tomatoes, break them up with a spoon or pulse briefly in a blender or with an immersion blender, then return to the skillet.
Bring the sauce to a boil, then reduce heat to low, partially cover, and simmer for 30 minutes, stirring occasionally.
Stir the 1/2 cup minced fresh parsley into the sauce, then remove from heat.
Preheat the oven to 375°F (190°C) and lightly smear some sauce on the bottom of a 9x13-inch baking pan.
Place a single layer of uncooked lasagna noodles in the pan, breaking to fit as needed.
Dot half the ricotta over the noodles in small mounds, spread about one-third of the remaining sauce over the ricotta, and sprinkle with half the mozzarella.
Repeat: add another layer of noodles, spread the rest of the ricotta, top with another one-third of the sauce, and sprinkle with the remaining mozzarella.
Add a final layer of noodles, spread the remaining sauce evenly over the top, and sprinkle with the 1/2 cup freshly grated Parmesan.
Bake uncovered until the lasagna is bubbly and the pasta is tender, about 45 minutes; if the top browns too much, cover loosely with foil for the last ~10 minutes.
Remove from the oven and let rest 5–10 minutes before cutting into squares and serving.
