Bring a large pot of salted water to a boil. Cook the spaghetti according to the package instructions until al dente. Drain well, reserving 1/2 cup of the starchy pasta water for the sauce.

While the pasta cooks, heat the olive oil in a large skillet or Dutch oven over medium-high heat. Add the chopped onion and sauté for 3 to 4 minutes until softened and translucent.

Add the minced garlic and ground beef to the skillet. Cook for 5 to 7 minutes, breaking the meat apart with a wooden spoon, until the beef is fully browned and no pink remains. Drain any excess grease from the pan.

Stir the tomato paste into the meat mixture and cook for 1 minute to deepen its flavor. Pour in the crushed tomatoes, beef broth, and dried oregano. Season with salt and black pepper to taste.

Reduce the heat to low and let the bolognese sauce simmer gently for 15 minutes to allow the flavors to meld. If the sauce becomes too thick, stir in a splash of the reserved pasta water.

Add the drained spaghetti directly to the skillet with the bolognese sauce, tossing thoroughly to coat the noodles. Serve immediately, garnished with grated parmesan cheese and fresh chopped basil.