Heat olive oil in a wide skillet, pan, or pot over medium heat. Add the diced onion and minced garlic, and sauté for about 3 minutes until they begin to brown and become fragrant.

Add the diced or crushed tomatoes, chicken broth, Italian basil, and spaghetti to the pan with the sautéed onion and garlic. Press the spaghetti with a spatula to fully submerge it in the liquid. If your cookware isn't wide enough, break the spaghetti in half. Cover with a lid, reduce the heat to medium-low, and cook for 8 minutes until the pasta is al dente. If the spaghetti is not done, add a bit more chicken broth and cook for another 1 to 2 minutes, covered. I like to occasionally stir the pasta to ensure it doesn't stick to the bottom.

Uncover the skillet and add salt. Turn off the heat, then top the pasta with freshly grated Parmesan cheese and chopped parsley. Serve the pasta immediately while hot.