Cook the Pasta: Boil a large pot of salted water and cook the spaghetti according to package instructions until al dente. Drain and set aside.
Prepare the Sauce: In a large skillet, heat olive oil over medium heat. Add the chopped onion, garlic, carrot, and celery, sautéing until softened (about 5 minutes).
Add Ground Beef: Increase the heat to medium-high and add the ground beef. Cook until browned, breaking it apart with a wooden spoon.
Combine Ingredients: Stir in the crushed tomatoes, tomato paste, oregano, basil, salt, and pepper. Bring to a simmer and reduce heat to low. Let it cook for 20-30 minutes, stirring occasionally.
Serve: Toss the cooked spaghetti with the sauce until well combined. Plate and garnish with fresh parsley and grated Parmesan cheese.
