Preheat oven to 375°F / 190°C (170°C fan-forced). Bring a large pot of salted water to a boil and cook the lasagna sheets to just al dente according to package directions (typically 8–10 minutes). Drain and lay flat on a lightly oiled sheet pan to prevent sticking.

While the noodles cook, heat the olive oil in a large non-stick skillet over medium heat. Add the sliced green onions and cook for 2–3 minutes until softened and lightly caramelised. Add the minced garlic and cook for 30 seconds until fragrant.

Add the ground turkey to the skillet, breaking it up with a spatula. Season with Italian seasoning, salt, and pepper. Cook for 6–8 minutes, stirring occasionally, until fully browned and an instant-read thermometer reads 165°F / 74°C with no pink remaining. Remove from heat.

While the pasta and meat continue to cook, mix the ricotta cheese, chopped spinach, and mushrooms together in a medium mixing bowl.

Once the pasta and meat are done cooking, lay out a lasagna noodle and spread the cheese mixture evenly with a spoon (about a spoonful and a half should do). Then add some ground turkey (roughly 1 spoonful), roll it up, and set aside. Repeat with all remaining noodles.

Spread ½ cup (125ml) of marinara sauce across the bottom of a 9x13 inch (23x33cm) baking dish. Place each rolled noodle seam-side down in the dish. Pour the remaining marinara sauce evenly over the roll-ups. Sprinkle with the shredded mozzarella, grated Parmesan, Italian seasoning, and crushed red pepper flakes.

Cover the dish with aluminium foil and bake for 15 minutes. Remove the foil and bake for a further 5–8 minutes until the cheese is melted and bubbling. Let the roll-ups rest for 5 minutes before serving.