Heat a large pot over medium-high heat. Add beef (1 1/2 pounds) to the pot, sprinkle with salt (1 1/2 teaspoons) and pepper (1/2 teaspoon), crumble into small chunks with a wooden spoon, and cook until lightly browned. Use a slotted spoon to transfer to a plate.
Drain all but 2 tablespoons of the fat from the pan and set over medium-low heat (if you don't have enough fat in the pan, add a tablespoon of olive oil). Add the onion (1 1/2 cups), bell pepper (1), and garlic (1 tablespoon) and cook, until the onion is translucent, about 7 minutes.
Return beef to pot then stir in crushed tomatoes (1 can), tomato sauce (1 can), tomato paste (1 can), Italian seasoning (1 tablespoon), and sugar (1/2 teaspoon). Bring sauce to a boil, then immediately reduce heat and simmer, uncovered for 1 hour. Adjust seasoning as needed.
Meanwhile cook spaghetti (16 ounces) in well-salted water, according to package instructions. Drain well and toss with sauce. Sprinkle with parsley (2 tablespoons) and serve. Pass grated Parmesan.
Notes
Beef: This recipe calls for 80/20 ground beef. What this means is the meat will be 80% beef and 20% fat. Normally, I'd say you can swap it out for a lower fat percentage (90/10 for instance), but the high-fat content is important to make sure you have some leftover in the pan to sear your veggies and garlic. Trust me, that add beef flavor will really go a long way!
Spaghetti Meat Sauce: A good rule of thumb in cooking if you want to get the most fully rounded flavor of an ingredient is to add that ingredient prepared in three different ways. For this sauce, we're using crushed tomatoes, tomato sauce, and tomato paste, which will give you the fresh bite of tomato, the seasoned heartiness of tomato, and the thick, concentrated flavor of the tomato. Your tastebuds will sing!
Where's the Oregano? I know I mentioned this spaghetti recipe with ground beef being flavored with oregano and basil -- but where are they in the ingredients list? Hidden in the Italian Seasoning!
Italian Seasoning is in the same class as chili spice -- it's actually a combination of different herbs. A few shakes of Italian Seasoning, and you'll get basil, oregano, thyme, and rosemary -- sometimes even marjoram!
No Spaghetti? No Problem! Forgot to get spaghetti noodles, or just don't want to use that particular pasta? No worries! There are hundreds of types of noodles to try, and this dish is very variation-friendly. Or you could go gluten-free with zucchini noodles or my personal favorite, spaghetti squash!