Bring a large pot of salted water to a boil. Cook the pasta according to package instructions until al dente. Drain, reserving ½ cup of pasta cooking water.
Prepare the Sauce:
Heat olive oil in a large skillet over medium heat. Sauté the onion for 2–3 minutes until soft. Add garlic and cook for 30 seconds until fragrant.
Add Tomatoes & Seasoning:
Stir in crushed tomatoes, tomato paste, oregano, red chili flakes (if using), salt, and pepper. Simmer for 4–5 minutes, adding reserved pasta water if the sauce is too thick.
Wilt the Spinach:
Toss in fresh spinach leaves and cook 1–2 minutes until just wilted.
Combine Pasta & Cheese:
Add cooked pasta to the skillet and stir to coat in the sauce. Mix in mozzarella and Parmesan until melted and gooey.
Serve & Garnish:
Transfer to bowls, top with extra mozzarella if desired, and sprinkle with fresh parsley. Serve immediately.
Serving and Storage Tips
