Heat olive oil in a large skillet or Dutch oven over medium-high heat. When the oil shimmers, add the ground beef, onion, and bell pepper. Break up the meat with a wooden spoon, and cook until the meat is no longer pink, about 7 minutes. Add the garlic and cook for 1 more minute. Drain off the excess fat.
Add the remaining ingredients to the skillet, as well as about ¾ teaspoon of salt and a dash of pepper.
Stir to combine; bring to a boil. Once the mixture boils, reduce the heat to a simmer. Cook, uncovered, for about 12-15 minutes, or until the noodles are tender and the sauce thickens.
Taste and season with additional salt and pepper, if necessary. Garnish with cheese and parsley, if desired.
Notes
Swap out the ground beef and use ground turkey, ground pork, ground sausage, or ground chicken instead.
In a pinch, vegetable broth or chicken broth will be a fine substitute for the beef broth.
For a dish that tastes like chili mac, substitute 2 teaspoons of chili powder for the Italian seasoning.
Make it spicy by adding a dash of cayenne or finishing the dish with crushed red pepper flakes.
Add a dash of paprika to the sauce, or season with fresh herbs such as parsley, rosemary, thyme, or basil.
For added texture, sprinkle cheese and a few buttered breadcrumbs over the top and then place the pot under the broiler. This will give it a crunchy, cheesy topping similar to baked mac and cheese.