In a Dutch oven or large pot, heat oil over medium-high. Add onion and ½ teaspoon salt and cook, stirring often, until onion begins to soften, 3 minutes. Stir in garlic, dried oregano and chili flakes and cook for 30 seconds.
Add the ground beef and cook, breaking up with a wooden spoon, until no longer pink, about 3 to 4 minutes. Pro tip: Make sure the meat is very crumbly (no big chunks remaining) so it has time to tenderize.
Stir in the tomato paste and cook for 1 minute. If you wish to add wine, add it now. Add crushed tomatoes, passata, broth, bay leaves, 1/2 teaspoon salt and 1/2 teaspoon black pepper. Give everything a stir, cover, and bring to a boil.
Once sauce is boiling, adjust lid so it's slightly ajar. Reduce heat to medium-low and simmer sauce for 20-30 minutes, stirring occasionally. Remove bay leaves and stir in grated parmesan and chopped fresh basil, if using. Taste and adjust the seasoning, if needed. Pro Tip: The longer the sauce cooks, the better so if you have time, let it go as long as possible.
When the sauce is almost finished cooking, boil the spaghetti (or pasta of choice) just until al dente. Drain and place portions of spaghetti on plates or bowls and generously ladle on the sauce.
Serve garnished with remaining basil leaves and extra parmesan cheese.
Notes
Broth: You can also use reduced-sodium Better Than Bouillon (either beef or chicken) mixed with water.
White wine: Not essential but will add a lot of flavor.
Serving options: Alternatively, use tongs to transfer spaghetti directly from the pot into the sauce, toss vigorously to combine, then serve directly from pot with parmesan cheese for topping.