Add the olive oil to a large dutch oven over medium-high heat. Add the ground beef, salt and pepper, and cook for 3-4 minutes, breaking it up as it cooks. If needed, discard excess grease from the pan, leaving behind 1-2 tablespoons.: You will hear a lively sizzle as the olive oil meets the hot surface and the ground beef goes in, releasing an immediate savory aroma. As the meat browns, the pan will produce little browned bits that smell nutty and meaty, and these are flavor gold for the sauce. Use a sturdy spoon to break the meat into bite sized pieces so it browns evenly rather than steaming. The visual cue to look for is that the beef changes from bright pink to a deep tan with some darker sear spots. If the pan seems overly greasy, carefully pour off excess fat until only a thin coating remains, leaving a tablespoon or two so the sauce remains flavorful. A common mistake is overcrowding the pan, which causes the meat to steam instead of brown, so work at medium high heat and give the meat room to sear.
Stir in the Italian seasoning and onion. Cook for another 3-4 minutes, or until the onion softens and becomes translucent. Add the garlic and cook for 1 minute, or until aromatic.: When the onion hits the pot, it should hiss faintly and begin to sweat, releasing a sweet, savory aroma as its edges turn glossy and translucent. The Italian seasoning will release herbal notes that marry with the meat. After the onion softens, adding the minced garlic will create a fragrant lift that you can smell right away; cook it just until you can smell that familiar roasted garlic scent, maybe a minute, because garlic burns quickly and will add bitterness if left too long. Look for softened onion pieces that have lost their raw crunch; that indicates readiness. A typical misstep here is adding garlic too early or cooking it at too high a heat, which gives a burnt, acrid flavor.
Stir in the diced tomatoes, passata, soy sauce, beef broth, and bay leaves. Bring the mixture to a boil, then reduce the heat to a simmer. Cover and simmer the sauce for 20 minutes, stirring occasionally.: As the canned diced tomatoes and passata hit the pan, the mixture will hiss and then settle into a rolling simmer. You will notice steam rising with a tangy tomato perfume that slowly softens into a deeper, rounded aroma as it cooks. The small addition of soy sauce will subtly deepen the savory base without announcing itself. Bringing it to a gentle boil first helps everything combine and activates the flavors, then lowering to a simmer ensures the sauce thickens slowly, developing body and complexity. Covering helps keep moisture even, but lift the lid occasionally to stir so nothing sticks to the bottom. Over boiling aggressively can reduce too quickly and leave the pasta without enough liquid later, so maintain a steady gentle simmer.
Add the macaroni and cook, covered, stirring occasionally, for 12-15 minutes or until the noodles are tender.: When you add the elbow macaroni , you will see the pasta sink into the tomato mixture and the surface will look fuller and cloudier as starches release. Keep the pot covered to trap heat and cook the pasta through in the sauce, which allows each piece to absorb flavor. Stir every few minutes to prevent the pasta from clumping and to redistribute heat, especially toward the end when the sauce thickens. The sensory cues are a thicker sauce, softened pasta that yields under a fork but still has slight bite, and a fragrant, cohesive aroma. Undercook and the pasta will feel chalky, overcook and it will be mushy, so start checking at 12 minutes for the right texture.
Stir in the cheese, garnish with parsley, and serve.: With the pot off the heat or on the lowest setting, stirring in shredded cheddar cheese will create ribbons of creamy orange melting through the sauce, adding a silky mouthfeel and rich finish. The temperature should be warm enough to melt the cheese but not so hot it separates; the ideal cue is a smooth, glossy texture. Finish with freshly chopped parsley for a bright, herbal contrast and a pop of color. A common error is adding cheese to a boiling pot, which can make it grainy, so remove from high heat before incorporating the cheese.